Prepare v6.1.0 release with updated cache dependency (#798)

Co-authored-by: HarithaVattikuti <73516759+HarithaVattikuti@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.github/workflows/e2e-tests.yml

@@ -747,7 +747,7 @@ jobs:
         operating-system: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - name: Checkout
-        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       - name: Clear toolcache
         shell: pwsh
         run: __tests__/clear-toolcache.ps1 ${{ runner.os }}
@@ -769,3 +769,24 @@ jobs:
             throw "Expected 9.0.100 to be reused, got '${{ steps.reuse.outputs.dotnet-version }}'."
           }
           __tests__/verify-dotnet.ps1 -Patterns "^9\.0\.100$"
+
+  test-skip-lts-prepass:
+    runs-on: ${{ matrix.operating-system }}
+    strategy:
+      fail-fast: false
+      matrix:
+        operating-system: [ubuntu-latest, windows-latest]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Clear toolcache
+        shell: pwsh
+        run: __tests__/clear-toolcache.ps1 ${{ runner.os }}
+      - name: Setup dotnet 9.0.308 with skip-lts-prepass
+        uses: ./
+        with:
+          dotnet-version: 9.0.308
+          skip-lts-prepass: true
+      - name: Verify dotnet
+        shell: pwsh
+        run: __tests__/verify-dotnet.ps1 -Patterns "^9\.0\.308$"

.licensed.yml

@@ -10,7 +10,7 @@ allowed:
   - mit
   - cc0-1.0
   - unlicense
-  - blueoak-1.0.0
+  - BlueOak-1.0.0
 
 reviewed:
   npm:

.licenses/npm/@actions/cache.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@actions/cache"
-version: 6.2.0
+version: 6.3.0
 type: npm
 summary: Actions cache lib
 homepage: https://github.com/actions/toolkit/tree/main/packages/cache

.licenses/npm/@actions/glob-0.6.1.dep.yml

@@ -1,20 +0,0 @@
----
-name: "@actions/glob"
-version: 0.6.1
-type: npm
-summary: Actions glob lib
-homepage: https://github.com/actions/toolkit/tree/main/packages/glob
-license: mit
-licenses:
-- sources: LICENSE.md
-  text: |-
-    The MIT License (MIT)
-
-    Copyright 2019 GitHub
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-notices: []

.licenses/npm/@azure/abort-controller.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/abort-controller"
-version: 2.1.2
+version: 2.2.0
 type: npm
 summary: Microsoft Azure SDK for JavaScript - Aborter
 homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/abort-controller/README.md
@@ -8,9 +8,9 @@ license: mit
 licenses:
 - sources: LICENSE
   text: |
-    The MIT License (MIT)
+    Copyright (c) Microsoft Corporation.
 
-    Copyright (c) 2020 Microsoft
+    MIT License
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -22,7 +22,7 @@ licenses:
     The above copyright notice and this permission notice shall be included in all
     copies or substantial portions of the Software.
 
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

.licenses/npm/@azure/core-auth.dep.yml

@@ -1,10 +1,10 @@
 ---
 name: "@azure/core-auth"
-version: 1.10.1
+version: 1.11.0
 type: npm
 summary: Provides low-level interfaces and helper methods for authentication in Azure
   SDK
-homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-auth/README.md
+homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/core-auth/README.md
 license: mit
 licenses:
 - sources: LICENSE

.licenses/npm/@azure/core-client.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/core-client"
-version: 1.10.2
+version: 1.11.1
 type: npm
 summary: Core library for interfacing with AutoRest generated code
 homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-client/

.licenses/npm/@azure/core-http-compat.dep.yml

@@ -1,9 +1,9 @@
 ---
 name: "@azure/core-http-compat"
-version: 2.4.0
+version: 2.5.0
 type: npm
 summary: Core HTTP Compatibility Library to bridge the gap between Core V1 & V2 packages.
-homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-compat/
+homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-http-compat/
 license: mit
 licenses:
 - sources: LICENSE

.licenses/npm/@azure/core-paging.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/core-paging"
-version: 1.6.2
+version: 1.7.0
 type: npm
 summary: Core types for paging async iterable iterators
 homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/core-paging/README.md
@@ -8,9 +8,9 @@ license: mit
 licenses:
 - sources: LICENSE
   text: |
-    The MIT License (MIT)
+    Copyright (c) Microsoft Corporation.
 
-    Copyright (c) 2020 Microsoft
+    MIT License
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -22,7 +22,7 @@ licenses:
     The above copyright notice and this permission notice shall be included in all
     copies or substantial portions of the Software.
 
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

.licenses/npm/@azure/core-rest-pipeline-1.23.0.dep.yml

@@ -0,0 +1,32 @@
+---
+name: "@azure/core-rest-pipeline"
+version: 1.23.0
+type: npm
+summary: Isomorphic client library for making HTTP requests in node.js and browser.
+homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-rest-pipeline/
+license: mit
+licenses:
+- sources: LICENSE
+  text: |
+    Copyright (c) Microsoft Corporation.
+
+    MIT License
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+notices: []

.licenses/npm/@azure/core-rest-pipeline-1.25.0.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/core-rest-pipeline"
-version: 1.24.0
+version: 1.25.0
 type: npm
 summary: Isomorphic client library for making HTTP requests in node.js and browser.
 homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/core-rest-pipeline/README.md

.licenses/npm/@azure/core-tracing.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/core-tracing"
-version: 1.3.1
+version: 1.4.0
 type: npm
 summary: Provides low-level interfaces and helper methods for tracing in Azure SDK
 homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-tracing/README.md

.licenses/npm/@azure/core-util.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/core-util"
-version: 1.13.1
+version: 1.14.0
 type: npm
 summary: Core library for shared utility methods
 homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-util/

.licenses/npm/@azure/core-xml.dep.yml

@@ -1,9 +1,9 @@
 ---
 name: "@azure/core-xml"
-version: 1.5.1
+version: 1.6.0
 type: npm
 summary: Core library for interacting with XML payloads
-homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/core/core-xml/
+homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/core-xml/README.md
 license: mit
 licenses:
 - sources: LICENSE

.licenses/npm/@azure/logger.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/logger"
-version: 1.3.0
+version: 1.4.0
 type: npm
 summary: Microsoft Azure SDK for JavaScript - Logger
 homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/logger/README.md

.licenses/npm/@azure/storage-blob.dep.yml

@@ -1,9 +1,9 @@
 ---
 name: "@azure/storage-blob"
-version: 12.32.0
+version: 12.31.0
 type: npm
 summary: Microsoft Azure Storage SDK for JavaScript - Blob
-homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/storage/storage-blob/README.md
+homepage: https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/storage/storage-blob/
 license: mit
 licenses:
 - sources: LICENSE

.licenses/npm/@azure/storage-common.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@azure/storage-common"
-version: 12.4.1
+version: 12.5.0
 type: npm
 summary: Azure Storage Common Client Library for JavaScript
 homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/storage/storage-common/README.md

.licenses/npm/@typespec/ts-http-runtime.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: "@typespec/ts-http-runtime"
-version: 0.3.6
+version: 0.3.9
 type: npm
 summary: Isomorphic client library for making HTTP requests in node.js and browser.
 homepage: https://github.com/Azure/azure-sdk-for-js/tree/main/sdk/core/ts-http-runtime/README.md

.licenses/npm/balanced-match-1.0.2.dep.yml

@@ -1,55 +0,0 @@
----
-name: balanced-match
-version: 1.0.2
-type: npm
-summary: Match balanced character pairs, like "{" and "}"
-homepage: https://github.com/juliangruber/balanced-match
-license: mit
-licenses:
-- sources: LICENSE.md
-  text: |
-    (MIT)
-
-    Copyright (c) 2013 Julian Gruber <julian@juliangruber.com>
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy of
-    this software and associated documentation files (the "Software"), to deal in
-    the Software without restriction, including without limitation the rights to
-    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-    of the Software, and to permit persons to whom the Software is furnished to do
-    so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-    SOFTWARE.
-- sources: README.md
-  text: |-
-    (MIT)
-
-    Copyright (c) 2013 Julian Gruber <julian@juliangruber.com>
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy of
-    this software and associated documentation files (the "Software"), to deal in
-    the Software without restriction, including without limitation the rights to
-    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-    of the Software, and to permit persons to whom the Software is furnished to do
-    so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-    SOFTWARE.
-notices: []

.licenses/npm/brace-expansion-1.1.18.dep.yml

@@ -1,55 +0,0 @@
----
-name: brace-expansion
-version: 1.1.18
-type: npm
-summary: Brace expansion as known from sh/bash
-homepage: https://github.com/juliangruber/brace-expansion
-license: mit
-licenses:
-- sources: LICENSE
-  text: |
-    MIT License
-
-    Copyright (c) 2013 Julian Gruber <julian@juliangruber.com>
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-    SOFTWARE.
-- sources: README.md
-  text: |-
-    (MIT)
-
-    Copyright (c) 2013 Julian Gruber &lt;julian@juliangruber.com&gt;
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy of
-    this software and associated documentation files (the "Software"), to deal in
-    the Software without restriction, including without limitation the rights to
-    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-    of the Software, and to permit persons to whom the Software is furnished to do
-    so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-    SOFTWARE.
-notices: []

.licenses/npm/brace-expansion.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: brace-expansion
-version: 5.0.9
+version: 5.0.12
 type: npm
 summary: Brace expansion as known from sh/bash
 homepage:

.licenses/npm/concat-map.dep.yml

@@ -1,31 +0,0 @@
----
-name: concat-map
-version: 0.0.1
-type: npm
-summary: concatenative mapdashery
-homepage: 
-license: other
-licenses:
-- sources: LICENSE
-  text: |
-    This software is released under the MIT license:
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy of
-    this software and associated documentation files (the "Software"), to deal in
-    the Software without restriction, including without limitation the rights to
-    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-    the Software, and to permit persons to whom the Software is furnished to do so,
-    subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-    FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-    COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-    IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-    CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-- sources: README.markdown
-  text: MIT
-notices: []

.licenses/npm/minimatch-3.1.5.dep.yml

@@ -1,26 +0,0 @@
----
-name: minimatch
-version: 3.1.5
-type: npm
-summary: a glob matcher in javascript
-homepage:
-license: isc
-licenses:
-- sources: LICENSE
-  text: |
-    The ISC License
-
-    Copyright (c) Isaac Z. Schlueter and Contributors
-
-    Permission to use, copy, modify, and/or distribute this software for any
-    purpose with or without fee is hereby granted, provided that the above
-    copyright notice and this permission notice appear in all copies.
-
-    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
-    IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-notices: []

.licenses/npm/minimatch.dep.yml

@@ -4,7 +4,7 @@ version: 10.2.5
 type: npm
 summary: a glob matcher in javascript
 homepage:
-license: blueoak-1.0.0
+license: BlueOak-1.0.0
 licenses:
 - sources: LICENSE.md
   text: |

.licenses/npm/undici.dep.yml

@@ -1,6 +1,6 @@
 ---
 name: undici
-version: 6.28.0
+version: 6.29.1
 type: npm
 summary: An HTTP/1.1 client, written from scratch for Node.js
 homepage: https://undici.nodejs.org

README.md

@@ -86,6 +86,21 @@ steps:
     dotnet-channel: LTS
 ```
 
+## Using the `skip-lts-prepass` input
+
+By default, `setup-dotnet` installs a minimal LTS runtime before installing the requested `dotnet-version`, to guarantee a stable `dotnet` executable is available. If your workflow doesn't need this safeguard (for example, the runner image already has a `dotnet` executable, or you're on a clean self-hosted/container environment and want to avoid the extra download), set `skip-lts-prepass: true` to install only the requested version.
+
+```yaml
+steps:
+- uses: actions/checkout@v7
+- uses: actions/setup-dotnet@v6
+  with:
+    dotnet-version: '9.0.x'
+    skip-lts-prepass: true
+```
+
+> **Note**: Setting skip-lts-prepass: true skips the LTS runtime pre-pass, so the action won't proactively install the latest LTS runtime. The existing dotnet executable and host components will be used if present; on a clean machine, they will come from the requested SDK installation. Consequently, dotnet --info may report a different Host: Version than when the pre-pass runs.
+
 ## Using the `architecture` input
 Using the architecture input, it is possible to specify the required .NET SDK architecture. Possible values:  `x64`, `x86`, `arm64`, `amd64`, `arm`, `s390x`, `ppc64le`, `riscv64`. If the input is not specified, the architecture defaults to the host OS architecture (not all of the architectures are available on all platforms).
 
@@ -312,7 +327,7 @@ The `workloads` input allows you to install .NET workloads as part of the SDK se
 
 ```yaml
 steps:
-- uses: actions/checkout@v5
+- uses: actions/checkout@v7
 - name: Setup .NET with workloads
   uses: actions/setup-dotnet@v6
   with:
@@ -437,7 +452,13 @@ You can also set `DOTNET_INSTALL_DIR` to a value based on runtime variables, suc
     - name: Set DOTNET_INSTALL_DIR
       run: echo "DOTNET_INSTALL_DIR=$HOME/.dotnet" >> $GITHUB_ENV
 ```
-> **Note**: On some self-hosted or large Linux runners, installing .NET under the default `/usr/share/dotnet` location may fail due to insufficient permissions. To ensure successful installation, set `DOTNET_INSTALL_DIR` to a user-writable path.
+> **Note**: On some self-hosted, larger or containerized runners the default location is not writable by the current user, and the installation fails with a permission error. The action resolves the install directory in this order:
+>
+> 1. `DOTNET_INSTALL_DIR`, when set. It is always honored and never probed.
+> 2. The default location for the runner OS, when it is writable.
+> 3. `.dotnet` in the current user's home directory, for example `/home/runner/.dotnet` or `C:\Users\runneradmin\.dotnet`.
+>
+> Runners that can write to the default location are unaffected. When the fallback is used, `DOTNET_ROOT` and `PATH` point at the home directory, so .NET preinstalled under the system location is no longer picked up. Set `DOTNET_INSTALL_DIR` explicitly to pin the location. If no writable location is found, the action warns and keeps the default, so the installation is likely to fail.
 
 ## Recommended permissions
 

__tests__/installer.test.ts

@@ -11,6 +11,7 @@ import {
 import each from 'jest-each';
 import semver from 'semver';
 import fspromises from 'fs/promises';
+import type {Stats} from 'fs';
 import os from 'os';
 import path from 'path';
 
@@ -35,26 +36,47 @@ jest.unstable_mockModule('@actions/io', () => ({
 jest.unstable_mockModule('fs', () => {
   const actual = jest.requireActual('fs') as typeof import('fs');
   const chmodSync = jest.fn();
+  const lstatSync = jest.fn(actual.lstatSync);
+  const mkdtempSync = jest.fn(actual.mkdtempSync);
+  const rmSync = jest.fn(actual.rmSync);
   const readdirSync = jest.fn();
   const existsSync = jest.fn(() => true);
   const statSync = jest.fn(() => ({isFile: () => true}));
   const accessSync = jest.fn();
-  return {
+  const mocked = {
     ...actual,
     chmodSync,
+    lstatSync,
+    mkdtempSync,
+    rmSync,
     readdirSync,
     existsSync,
     statSync,
-    accessSync,
-    default: {
-      ...actual,
-      chmodSync,
-      readdirSync,
-      existsSync,
-      statSync,
-      accessSync
-    }
+    accessSync
   };
+  return {
+    ...mocked,
+    default: mocked
+  };
+});
+
+jest.unstable_mockModule('os', () => {
+  const actual = jest.requireActual('os') as typeof import('os');
+  // os.homedir() reads the real environment, not jest's process.env.
+  const homedir = jest.fn(actual.homedir);
+  // Resolved per call, so spies placed on the real module still take effect.
+  const arch = () => actual.arch();
+  return {...actual, homedir, arch, default: {...actual, homedir, arch}};
+});
+
+// Allows tests to re-import the installer as if running on another OS.
+let platformOverride: 'windows' | 'linux' | 'mac' | undefined;
+jest.unstable_mockModule('../src/utils.js', () => {
+  const actual = jest.requireActual(
+    '../src/utils.js'
+  ) as typeof import('../src/utils.js');
+  const platform = platformOverride ?? actual.PLATFORM;
+  return {...actual, PLATFORM: platform, IS_WINDOWS: platform === 'windows'};
 });
 
 const exec = await import('@actions/exec');
@@ -1218,6 +1240,135 @@ describe('installer tests', () => {
           }
         );
       });
+
+      describe('skip-lts-prepass tests', () => {
+        it('should run the LTS pre-pass by default (skip-lts-prepass not set)', async () => {
+          const inputVersion = '9.0.100';
+          const inputQuality = '';
+          const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+          getExecOutputSpy.mockImplementation(() => {
+            return Promise.resolve({exitCode: 0, stdout, stderr: ''});
+          });
+          maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+          const dotnetInstaller = new installer.DotnetCoreInstaller(
+            inputVersion,
+            inputQuality
+          );
+          await dotnetInstaller.installDotnet();
+
+          expect(getExecOutputSpy).toHaveBeenCalledTimes(2);
+          const ltsCallArguments = (
+            getExecOutputSpy.mock.calls[0][1] as string[]
+          ).join(' ');
+          expect(ltsCallArguments).toContain(
+            IS_WINDOWS ? '-Channel LTS' : '--channel LTS'
+          );
+        });
+
+        it('should skip the LTS pre-pass and install only the requested version when skip-lts-prepass is true', async () => {
+          const inputVersion = '9.0.100';
+          const inputQuality = '';
+          const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+          getExecOutputSpy.mockImplementation(() => {
+            return Promise.resolve({exitCode: 0, stdout, stderr: ''});
+          });
+          maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+          const dotnetInstaller = new installer.DotnetCoreInstaller(
+            inputVersion,
+            inputQuality,
+            undefined,
+            undefined,
+            true,
+            undefined,
+            undefined,
+            true
+          );
+          const installedVersion = await dotnetInstaller.installDotnet();
+
+          expect(getExecOutputSpy).toHaveBeenCalledTimes(1);
+          const scriptArguments = (
+            getExecOutputSpy.mock.calls[0][1] as string[]
+          ).join(' ');
+          expect(scriptArguments).not.toContain('LTS');
+          expect(scriptArguments).toContain(
+            IS_WINDOWS
+              ? `-Version ${inputVersion}`
+              : `--version ${inputVersion}`
+          );
+          expect(installedVersion).toBe(inputVersion);
+        });
+
+        it('should skip the LTS pre-pass for a cross-architecture install', async () => {
+          const inputVersion = '9.0.100';
+          const inputQuality = '';
+          const inputArchitecture =
+            installer.normalizeArch(os.arch()) === 'x64' ? 'arm64' : 'x64';
+          const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+          getExecOutputSpy.mockImplementation(() => {
+            return Promise.resolve({exitCode: 0, stdout, stderr: ''});
+          });
+          maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+          const dotnetInstaller = new installer.DotnetCoreInstaller(
+            inputVersion,
+            inputQuality,
+            inputArchitecture,
+            undefined,
+            true,
+            undefined,
+            undefined,
+            true
+          );
+          await dotnetInstaller.installDotnet();
+
+          expect(getExecOutputSpy).toHaveBeenCalledTimes(1);
+          const scriptArguments = (
+            getExecOutputSpy.mock.calls[0][1] as string[]
+          ).join(' ');
+          expect(scriptArguments).not.toContain('LTS');
+          expect(scriptArguments).toContain(
+            IS_WINDOWS ? '-Architecture' : '--architecture'
+          );
+        });
+
+        it('should skip the LTS pre-pass for each requested version', async () => {
+          const inputQuality = '';
+
+          getExecOutputSpy.mockImplementation(() => {
+            return Promise.resolve({
+              exitCode: 0,
+              stdout: `Fictitious dotnet version installed`,
+              stderr: ''
+            });
+          });
+          maxSatisfyingSpy.mockImplementation(() => '9.0.100');
+
+          for (const version of ['8.0.100', '9.0.100']) {
+            const dotnetInstaller = new installer.DotnetCoreInstaller(
+              version,
+              inputQuality,
+              undefined,
+              undefined,
+              true,
+              undefined,
+              undefined,
+              true
+            );
+            await dotnetInstaller.installDotnet();
+          }
+
+          // 2 versions x 1 call each (no LTS pre-pass call for either)
+          expect(getExecOutputSpy).toHaveBeenCalledTimes(2);
+          for (const call of getExecOutputSpy.mock.calls) {
+            expect((call[1] as string[]).join(' ')).not.toContain('LTS');
+          }
+        });
+      });
     });
 
     describe('addToPath() tests', () => {
@@ -1235,6 +1386,240 @@ describe('installer tests', () => {
         expect(path).toContain(process.env['DOTNET_INSTALL_DIR']);
       });
     });
+
+    describe('install directory fallback tests', () => {
+      // Mock factories re-run on resetModules, so the installer sees new
+      // instances; configure those, not the ones captured at file load.
+      const importInstallerFor = async (
+        platform: 'windows' | 'linux' | 'mac',
+        isWritable: (dir: string) => boolean
+      ) => {
+        platformOverride = platform;
+        jest.resetModules();
+
+        const freshFs = await import('fs');
+        (freshFs.lstatSync as jest.Mock).mockReturnValue({} as Stats);
+        (freshFs.mkdtempSync as jest.Mock).mockImplementation(
+          (...args: unknown[]) => {
+            const prefix = String(args[0]);
+            if (!isWritable(path.dirname(prefix))) {
+              throw Object.assign(new Error('permission denied'), {
+                code: 'EACCES'
+              });
+            }
+            return `${prefix}abc123`;
+          }
+        );
+        (freshFs.rmSync as jest.Mock).mockImplementation(() => {});
+
+        const freshCore = await import('@actions/core');
+        const freshOs = await import('os');
+        const {DotnetInstallDir} = await import('../src/installer.js');
+
+        return {DotnetInstallDir, core: freshCore, fs: freshFs, os: freshOs};
+      };
+
+      const probedDirs = (freshFs: typeof import('fs')) =>
+        (freshFs.mkdtempSync as jest.Mock).mock.calls.map(call =>
+          path.dirname(String(call[0]))
+        );
+
+      beforeEach(() => {
+        delete process.env['DOTNET_INSTALL_DIR'];
+      });
+
+      afterEach(() => {
+        platformOverride = undefined;
+      });
+
+      it(`should use the default location when it is writable`, async () => {
+        const {DotnetInstallDir} = await importInstallerFor(
+          'linux',
+          () => true
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe('/usr/share/dotnet');
+      });
+
+      it(`should fall back to the home directory when the default location is not writable`, async () => {
+        const fallbackPath = path.join(os.homedir(), '.dotnet');
+        const {DotnetInstallDir, core: freshCore} = await importInstallerFor(
+          'linux',
+          dir => dir === fallbackPath
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe(fallbackPath);
+        expect(freshCore.warning).toHaveBeenCalled();
+      });
+
+      it(`should reject a dangling symlink instead of probing its writable parent`, async () => {
+        // Resolved, because that is the form the probe receives on every platform.
+        const linkPath = path.resolve('/usr/share/dotnet');
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'linux',
+          () => true
+        );
+        // A dangling link exists for lstat, but nothing can be created under it.
+        (freshFs.mkdtempSync as jest.Mock).mockImplementation(
+          (...args: unknown[]) => {
+            if (path.dirname(String(args[0])) === linkPath) {
+              throw Object.assign(new Error('no such file or directory'), {
+                code: 'ENOENT'
+              });
+            }
+            return `${args[0]}abc123`;
+          }
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe(
+          path.join(os.homedir(), '.dotnet')
+        );
+        const probed = probedDirs(freshFs);
+        expect(probed).toContain(linkPath);
+        expect(probed).not.toContain(path.dirname(linkPath));
+      });
+
+      it(`should probe the nearest existing parent when the directory is missing`, async () => {
+        const systemPath = path.resolve('/usr/share/dotnet');
+        const parentPath = path.dirname(systemPath);
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'linux',
+          () => true
+        );
+        // Only the parent exists, so the walk has to climb before probing.
+        (freshFs.lstatSync as jest.Mock).mockImplementation(
+          (...args: unknown[]) =>
+            path.resolve(String(args[0])) === parentPath
+              ? ({} as Stats)
+              : undefined
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe('/usr/share/dotnet');
+        const probed = probedDirs(freshFs);
+        expect(probed).toContain(parentPath);
+        expect(probed).not.toContain(systemPath);
+      });
+
+      it(`should give up at the filesystem root when no ancestor exists`, async () => {
+        const systemPath = path.resolve('/usr/share/dotnet');
+        const homePath = path.join(os.homedir(), '.dotnet');
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'linux',
+          () => true
+        );
+        // Nothing on the system path exists, all the way up to the root.
+        (freshFs.lstatSync as jest.Mock).mockImplementation(
+          (...args: unknown[]) =>
+            systemPath.startsWith(path.resolve(String(args[0])))
+              ? undefined
+              : ({} as Stats)
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe(homePath);
+        // The walk hit the root and returned without ever probing.
+        expect(probedDirs(freshFs)).toEqual([homePath]);
+      });
+
+      it(`should not probe a relative default location`, async () => {
+        // An unset HOME makes the macOS default relative, e.g. 'undefined/.dotnet'.
+        delete process.env['HOME'];
+        const homePath = path.join(os.homedir(), '.dotnet');
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'mac',
+          () => true
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe(homePath);
+        expect(probedDirs(freshFs)).not.toContain(process.cwd());
+      });
+
+      it(`should not probe a relative default location on Windows`, async () => {
+        // An unset PROGRAMFILES makes the Windows default relative.
+        delete process.env['PROGRAMFILES'];
+        const homePath = path.join(os.homedir(), '.dotnet');
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'windows',
+          () => true
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe(homePath);
+        expect(probedDirs(freshFs)).not.toContain(process.cwd());
+      });
+
+      it(`should not treat the filesystem root as a home directory`, async () => {
+        const root = path.parse(process.cwd()).root;
+        const rootDotnet = path.join(root, '.dotnet');
+        // Only the root candidate is writable, so an unguarded run would pick it.
+        const {
+          DotnetInstallDir,
+          os: freshOs,
+          core: freshCore
+        } = await importInstallerFor('linux', dir => dir === rootDotnet);
+        (freshOs.homedir as jest.Mock).mockReturnValue(root);
+
+        expect(DotnetInstallDir.dirPath).toBe('/usr/share/dotnet');
+        expect(freshCore.warning).toHaveBeenCalled();
+      });
+
+      it(`should still report writable when the probe cannot be removed`, async () => {
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'linux',
+          () => true
+        );
+        (freshFs.rmSync as jest.Mock).mockImplementation(() => {
+          throw Object.assign(new Error('device or resource busy'), {
+            code: 'EBUSY'
+          });
+        });
+
+        expect(DotnetInstallDir.dirPath).toBe('/usr/share/dotnet');
+      });
+
+      it(`should keep the shared macOS location and warn when it is not writable`, async () => {
+        // The mac default derives from HOME, homeInstallPath() from os.homedir();
+        // aligning them is what makes both candidates the same path.
+        process.env['HOME'] = os.homedir();
+        const homePath = path.join(os.homedir(), '.dotnet');
+        const {
+          DotnetInstallDir,
+          fs: freshFs,
+          core: freshCore
+        } = await importInstallerFor('mac', () => false);
+
+        expect(DotnetInstallDir.dirPath).toBe(homePath);
+        // One candidate, so it is probed once rather than twice.
+        expect(probedDirs(freshFs)).toEqual([homePath]);
+        expect(freshCore.warning).toHaveBeenCalled();
+      });
+
+      it(`should prefer DOTNET_INSTALL_DIR env.var without probing`, async () => {
+        process.env['DOTNET_INSTALL_DIR'] = path.join(path.sep, 'custom');
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'linux',
+          () => false
+        );
+
+        expect(DotnetInstallDir.dirPath).toBe(path.join(path.sep, 'custom'));
+        expect(freshFs.mkdtempSync as jest.Mock).not.toHaveBeenCalled();
+      });
+
+      it(`should resolve once, and not before the directory is needed`, async () => {
+        const {DotnetInstallDir, fs: freshFs} = await importInstallerFor(
+          'linux',
+          () => true
+        );
+        const probe = freshFs.mkdtempSync as jest.Mock;
+
+        expect(probe).not.toHaveBeenCalled();
+
+        void DotnetInstallDir.dirPath;
+        const afterFirstRead = probe.mock.calls.length;
+        void DotnetInstallDir.dirPath;
+
+        expect(afterFirstRead).toBeGreaterThan(0);
+        expect(probe.mock.calls.length).toBe(afterFirstRead);
+      });
+    });
   });
 
   describe('normalizeArch() tests', () => {

__tests__/setup-dotnet.test.ts

@@ -315,6 +315,44 @@ describe('setup-dotnet tests', () => {
       expect(capturedCheckLatest).toBe(false);
     });
 
+    it("should read the 'skip-lts-prepass' input and pass it to DotnetCoreInstaller", async () => {
+      inputs['dotnet-version'] = ['10.0.101'];
+      inputs['dotnet-quality'] = '';
+      inputs['architecture'] = '';
+      inputs['skip-lts-prepass'] = 'true';
+
+      let capturedSkipLtsPrepass: boolean | undefined;
+      installDotnetSpy.mockImplementation(function (this: any) {
+        capturedSkipLtsPrepass = this.skipLtsPrepass;
+        return Promise.resolve('');
+      });
+
+      await setup.run();
+
+      expect(getBooleanInputSpy).toHaveBeenCalledWith('skip-lts-prepass');
+      expect(installDotnetSpy).toHaveBeenCalledTimes(1);
+      expect(capturedSkipLtsPrepass).toBe(true);
+    });
+
+    it("should default 'skip-lts-prepass' to false when the input isn't set", async () => {
+      inputs['dotnet-version'] = ['10.0.101'];
+      inputs['dotnet-quality'] = '';
+      inputs['architecture'] = '';
+      inputs['skip-lts-prepass'] = '';
+
+      let capturedSkipLtsPrepass: boolean | undefined;
+      installDotnetSpy.mockImplementation(function (this: any) {
+        capturedSkipLtsPrepass = this.skipLtsPrepass;
+        return Promise.resolve('');
+      });
+
+      await setup.run();
+
+      expect(getBooleanInputSpy).toHaveBeenCalledWith('skip-lts-prepass');
+      expect(installDotnetSpy).toHaveBeenCalledTimes(1);
+      expect(capturedSkipLtsPrepass).toBe(false);
+    });
+
     describe("'check-latest' resolution", () => {
       const captureCheckLatest = async () => {
         inputs['dotnet-version'] = ['10.0.101'];

action.yml

@@ -14,6 +14,10 @@ inputs:
   dotnet-channel:
     description: 'Optional channel for the installation. The possible values are: STS, LTS, A.B (e.g. 8.0), A.B.Cxx (e.g. 8.0.1xx, available since 5.0). To be used with "dotnet-version: latest".'
     required: false
+  skip-lts-prepass:
+    description: 'Optional. When true, skips the LTS runtime pre-pass and installs only the requested dotnet-version. Default: false.'
+    required: false
+    default: false
   global-json-file:
     description: 'Optional global.json location, if your global.json isn''t located in the root of the repo.'
     required: false

package-lock.json

@@ -1,15 +1,15 @@
 {
   "name": "setup-dotnet",
-  "version": "6.0.0",
+  "version": "6.1.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "setup-dotnet",
-      "version": "6.0.0",
+      "version": "6.1.0",
       "license": "MIT",
       "dependencies": {
-        "@actions/cache": "^6.2.0",
+        "@actions/cache": "^6.3.0",
         "@actions/core": "^3.0.1",
         "@actions/exec": "^3.0.0",
         "@actions/github": "^9.1.1",
@@ -56,30 +56,20 @@
       }
     },
     "node_modules/@actions/cache": {
-      "version": "6.2.0",
-      "resolved": "https://registry.npmjs.org/@actions/cache/-/cache-6.2.0.tgz",
-      "integrity": "sha512-Nv0xWRmbxfDbAn/70flO/F6tj2Nv4XTYMAsQHiDFSojCDfso/Zni+fRKa14ToI9hnmOW/rQcY1WYb6wsM7Pgwg==",
+      "version": "6.3.0",
+      "resolved": "https://registry.npmjs.org/@actions/cache/-/cache-6.3.0.tgz",
+      "integrity": "sha512-SJKaVMqTgetQgJF0wifi5N2+2mffCLy/D4w/3sJtRanBBGECdi1/OD0wswyLVmqEmPbYB/rVJk41Qn/xEbFjAw==",
       "license": "MIT",
       "dependencies": {
         "@actions/core": "^3.0.1",
         "@actions/exec": "^3.0.0",
-        "@actions/glob": "^0.6.1",
+        "@actions/glob": "^0.7.0",
         "@actions/http-client": "^4.0.1",
         "@actions/io": "^3.0.2",
-        "@azure/core-rest-pipeline": "^1.23.0",
-        "@azure/storage-blob": "^12.31.0",
+        "@azure/core-rest-pipeline": "~1.23.0",
+        "@azure/storage-blob": "~12.31.0",
         "@protobuf-ts/runtime-rpc": "^2.11.1",
-        "semver": "^7.7.4"
-      }
-    },
-    "node_modules/@actions/cache/node_modules/@actions/glob": {
-      "version": "0.6.1",
-      "resolved": "https://registry.npmjs.org/@actions/glob/-/glob-0.6.1.tgz",
-      "integrity": "sha512-K4+2Ac5ILcf2ySdJCha+Pop9NcKjxqCL4xL4zI50dgB2PbXgC0+AcP011xfH4Of6b4QEJJg8dyZYv7zl4byTsw==",
-      "license": "MIT",
-      "dependencies": {
-        "@actions/core": "^3.0.0",
-        "minimatch": "^3.0.4"
+        "semver": "^7.8.5"
       }
     },
     "node_modules/@actions/core": {
@@ -168,21 +158,21 @@
       "license": "MIT"
     },
     "node_modules/@azure/abort-controller": {
-      "version": "2.1.2",
-      "resolved": "https://registry.npmjs.org/@azure/abort-controller/-/abort-controller-2.1.2.tgz",
-      "integrity": "sha512-nBrLsEWm4J2u5LpAPjxADTlq3trDgVZZXHNKabeXZtpq3d3AbN/KGO82R87rdDz5/lYB024rtEf10/q0urNgsA==",
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@azure/abort-controller/-/abort-controller-2.2.0.tgz",
+      "integrity": "sha512-fNAjWnA/nZ2jz31kxR/AqRaUT8ewHBw/WuBIosK0moMy1C9e5ValbDfFdIxJzVOOYaYkV/b2F1S4H/aHiqfVQg==",
       "license": "MIT",
       "dependencies": {
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=18.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/core-auth": {
-      "version": "1.10.1",
-      "resolved": "https://registry.npmjs.org/@azure/core-auth/-/core-auth-1.10.1.tgz",
-      "integrity": "sha512-ykRMW8PjVAn+RS6ww5cmK9U2CyH9p4Q88YJwvUslfuMmN98w/2rdGRLPqJYObapBCdzBVeDgYWdJnFPFb7qzpg==",
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-auth/-/core-auth-1.11.0.tgz",
+      "integrity": "sha512-IUZydyTUkDnYdstOW9pFOOUQlBjAepK5teihDE3x6yxsPJs/hsAaaYpeGxdxrgtOiJbBKSjKW7MDk7AEhb4LRg==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2",
@@ -190,13 +180,13 @@
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/core-client": {
-      "version": "1.10.2",
-      "resolved": "https://registry.npmjs.org/@azure/core-client/-/core-client-1.10.2.tgz",
-      "integrity": "sha512-1D2LpsU7y9xrqKjdIbsB7PlrRePw0xsVV8p+AKTlzITrWmscajryfJCdDJB/oGwvDI5HmRo04eMMADB67uwAwQ==",
+      "version": "1.11.1",
+      "resolved": "https://registry.npmjs.org/@azure/core-client/-/core-client-1.11.1.tgz",
+      "integrity": "sha512-2QygG2F76ZpMP2eMztiJvAiFMu71M9rDeU7vO/QKg5Css7MgM4frUOslFjhVjRhbGaCNPtz/S8M6y46/fFKVuQ==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2",
@@ -208,19 +198,19 @@
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/core-http-compat": {
-      "version": "2.4.0",
-      "resolved": "https://registry.npmjs.org/@azure/core-http-compat/-/core-http-compat-2.4.0.tgz",
-      "integrity": "sha512-f1P96IB399YiN2ARYHP7EpZi3Bf3wH4SN2lGzrw7JVwm7bbsVYtf2iKSBwTywD2P62NOPZGHFSZi+6jjb75JuA==",
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-http-compat/-/core-http-compat-2.5.0.tgz",
+      "integrity": "sha512-BoSmXPx2er1Ai+wKlDvj29jIQespCNBwEmKyZVHO2kEFsWbGjAjwMCGzug3DJM5/QYIV3vej0S1zcU5bq9fa8w==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       },
       "peerDependencies": {
         "@azure/core-client": "^1.10.0",
@@ -243,21 +233,21 @@
       }
     },
     "node_modules/@azure/core-paging": {
-      "version": "1.6.2",
-      "resolved": "https://registry.npmjs.org/@azure/core-paging/-/core-paging-1.6.2.tgz",
-      "integrity": "sha512-YKWi9YuCU04B55h25cnOYZHxXYtEvQEbKST5vqRga7hWY9ydd3FZHdeQF8pyh+acWZvppw13M/LMGx0LABUVMA==",
+      "version": "1.7.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-paging/-/core-paging-1.7.0.tgz",
+      "integrity": "sha512-7GEAoIsaoBr6KELNRb8nypowCqvk8dnCHFCYg4XD4lOQGY2GqjQg5IhkRjyBFRO18CGSMq05PaNqSOE9GQro3g==",
       "license": "MIT",
       "dependencies": {
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=18.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/core-rest-pipeline": {
-      "version": "1.24.0",
-      "resolved": "https://registry.npmjs.org/@azure/core-rest-pipeline/-/core-rest-pipeline-1.24.0.tgz",
-      "integrity": "sha512-PpLsoDQ3AMmKZ0VU+0GrmqMxgp/sExjlVm4R+nLWngeoEGAzOIPVifaxKGU5gMv+nWELUoHfvrolWD+ZS/nFJg==",
+      "version": "1.23.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-rest-pipeline/-/core-rest-pipeline-1.23.0.tgz",
+      "integrity": "sha512-Evs1INHo+jUjwHi1T6SG6Ua/LHOQBCLuKEEE6efIpt4ZOoNonaT1kP32GoOcdNDbfqsD2445CPri3MubBy5DEQ==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2",
@@ -273,21 +263,21 @@
       }
     },
     "node_modules/@azure/core-tracing": {
-      "version": "1.3.1",
-      "resolved": "https://registry.npmjs.org/@azure/core-tracing/-/core-tracing-1.3.1.tgz",
-      "integrity": "sha512-9MWKevR7Hz8kNzzPLfX4EAtGM2b8mr50HPDBvio96bURP/9C+HjdH3sBlLSNNrvRAr5/k/svoH457gB5IKpmwQ==",
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-tracing/-/core-tracing-1.4.0.tgz",
+      "integrity": "sha512-eGwxD0AtncrxeBM4tG8R55Pc3rdX1hNW2WibJAgYpCVA6E93mvvVH+LcssoVjOBrSKWS55yEIHsk0X8ctHmfOQ==",
       "license": "MIT",
       "dependencies": {
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/core-util": {
-      "version": "1.13.1",
-      "resolved": "https://registry.npmjs.org/@azure/core-util/-/core-util-1.13.1.tgz",
-      "integrity": "sha512-XPArKLzsvl0Hf0CaGyKHUyVgF7oDnhKoP85Xv6M4StF/1AhfORhZudHtOyf2s+FcbuQ9dPRAjB8J2KvRRMUK2A==",
+      "version": "1.14.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-util/-/core-util-1.14.0.tgz",
+      "integrity": "sha512-9n2pWK61veAuN0V20t9lOuoV4CFMdyAZ1ygZzvBGk/pBBJRib/PjL9PLXa/aI2CcPpyHfqVsxxqLCYl6uZlfDw==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2",
@@ -295,39 +285,39 @@
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/core-xml": {
-      "version": "1.5.1",
-      "resolved": "https://registry.npmjs.org/@azure/core-xml/-/core-xml-1.5.1.tgz",
-      "integrity": "sha512-xcNRHqCoSp4AunOALEae6A8f3qATb83gSrm31Iqb01OzblvC3/W/bfXozcq78EzIdzZzuH1bZ2NvRR0TdX709w==",
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-xml/-/core-xml-1.6.0.tgz",
+      "integrity": "sha512-e7lX/dk//F6Qf7BB6PTY4+p2yuOQtyOeHGyapYHNwqSp2OnYpwQt49A/Nin2XmKBQ69pwagR4k/lQBq8lbHQkA==",
       "license": "MIT",
       "dependencies": {
         "fast-xml-parser": "^5.5.9",
         "tslib": "^2.8.1"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/logger": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/@azure/logger/-/logger-1.3.0.tgz",
-      "integrity": "sha512-fCqPIfOcLE+CGqGPd66c8bZpwAji98tZ4JI9i/mlTNTlsIWslCfpg48s/ypyLxZTump5sypjrKn2/kY7q8oAbA==",
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/@azure/logger/-/logger-1.4.0.tgz",
+      "integrity": "sha512-rbAE25KUfjU/s3XHUdJgceoCP5dEOpMx85J04kF+QMdta73XkuG9JGHHinch+XIoKpBdqljin+KqURpJriSzLA==",
       "license": "MIT",
       "dependencies": {
         "@typespec/ts-http-runtime": "^0.3.0",
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@azure/storage-blob": {
-      "version": "12.32.0",
-      "resolved": "https://registry.npmjs.org/@azure/storage-blob/-/storage-blob-12.32.0.tgz",
-      "integrity": "sha512-80LzSNnFQye2LCCBFghAJS6jJQJ7N4bfgZ6qDMgVGRtugZ7TLDKQZ2hczMigmZH3jAcMRdma/IygsC5+0gT7Tw==",
+      "version": "12.31.0",
+      "resolved": "https://registry.npmjs.org/@azure/storage-blob/-/storage-blob-12.31.0.tgz",
+      "integrity": "sha512-DBgNv10aCSxopt92DkTDD0o9xScXeBqPKGmR50FPZQaEcH4JLQ+GEOGEDv19V5BMkB7kxr+m4h6il/cCDPvmHg==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2",
@@ -341,7 +331,7 @@
         "@azure/core-util": "^1.11.0",
         "@azure/core-xml": "^1.4.5",
         "@azure/logger": "^1.1.4",
-        "@azure/storage-common": "^12.4.0",
+        "@azure/storage-common": "^12.3.0",
         "events": "^3.0.0",
         "tslib": "^2.8.1"
       },
@@ -350,14 +340,14 @@
       }
     },
     "node_modules/@azure/storage-common": {
-      "version": "12.4.1",
-      "resolved": "https://registry.npmjs.org/@azure/storage-common/-/storage-common-12.4.1.tgz",
-      "integrity": "sha512-t14unw/WofGDUi7TKJrsyXyPsN+NLgRm7hMaq0llxNmTIzt7f257+6LE6FKIJPh88zLj6M7LPvzve0fEYg/L3A==",
+      "version": "12.5.0",
+      "resolved": "https://registry.npmjs.org/@azure/storage-common/-/storage-common-12.5.0.tgz",
+      "integrity": "sha512-bttzuhQiCIwrkzjPDA+AtAR7dg19L/CC6ztcqJ5LfvWpXuys9mHp0UQ0udYnoUvv9SCT9KTR5kqFvFr0e6k0lQ==",
       "license": "MIT",
       "dependencies": {
         "@azure/abort-controller": "^2.1.2",
         "@azure/core-auth": "^1.9.0",
-        "@azure/core-http-compat": "^2.2.0",
+        "@azure/core-http-compat": "^2.4.0",
         "@azure/core-rest-pipeline": "^1.24.0",
         "@azure/core-tracing": "^1.2.0",
         "@azure/core-util": "^1.11.0",
@@ -366,7 +356,25 @@
         "tslib": "^2.8.1"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
+      }
+    },
+    "node_modules/@azure/storage-common/node_modules/@azure/core-rest-pipeline": {
+      "version": "1.25.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-rest-pipeline/-/core-rest-pipeline-1.25.0.tgz",
+      "integrity": "sha512-bMs8ekJLjX8wPV+9IPBges1SLPyuDtE9g5gLDWOpxzKcoOFQnpLGkbcT1tdw3FaAmDS1gnPmMmJ6y/T5B96kIA==",
+      "license": "MIT",
+      "dependencies": {
+        "@azure/abort-controller": "^2.1.2",
+        "@azure/core-auth": "^1.10.0",
+        "@azure/core-tracing": "^1.3.0",
+        "@azure/core-util": "^1.13.0",
+        "@azure/logger": "^1.3.0",
+        "@typespec/ts-http-runtime": "^0.3.4",
+        "tslib": "^2.6.2"
+      },
+      "engines": {
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@babel/code-frame": {
@@ -2289,9 +2297,9 @@
       }
     },
     "node_modules/@typespec/ts-http-runtime": {
-      "version": "0.3.6",
-      "resolved": "https://registry.npmjs.org/@typespec/ts-http-runtime/-/ts-http-runtime-0.3.6.tgz",
-      "integrity": "sha512-jIXhD0eWQ1JA6ln/5Dltyx22UxWNrw0hZmhy2rlv6m6KgF7kplHx3g0fzi09lNmTJQRR91OlemYp3xFnvDK9og==",
+      "version": "0.3.9",
+      "resolved": "https://registry.npmjs.org/@typespec/ts-http-runtime/-/ts-http-runtime-0.3.9.tgz",
+      "integrity": "sha512-edSdeAqkdxBVzA1yL1LrLCml1YjyCVvPMtMqJpbF+6K609tHe8V6sQUzFQSGcYNhcuhOceZtjvN32+mpIth30A==",
       "license": "MIT",
       "dependencies": {
         "http-proxy-agent": "^7.0.0",
@@ -2299,7 +2307,7 @@
         "tslib": "^2.6.2"
       },
       "engines": {
-        "node": ">=20.0.0"
+        "node": ">=22.0.0"
       }
     },
     "node_modules/@ungap/structured-clone": {
@@ -2888,9 +2896,9 @@
       "license": "Apache-2.0"
     },
     "node_modules/brace-expansion": {
-      "version": "5.0.9",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.9.tgz",
-      "integrity": "sha512-ScQ4IuvIEF1TMlP7Zt+vjJ//9zlPb2SDcxWxM3bk8s6t6GGdJ7KO1dCcTidOPJKePW30LE/2cT7wCyPho9/Wxg==",
+      "version": "5.0.12",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.12.tgz",
+      "integrity": "sha512-YovQ3rzhaLMIrDjNDMkNS01tea93qhEhG5xy8f6+R0l+dw3Ki+5sCoIoI942iuLZTHWogWktgwVDhU09iNEimQ==",
       "license": "MIT",
       "dependencies": {
         "balanced-match": "^4.0.2"
@@ -3183,6 +3191,7 @@
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
       "integrity": "sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==",
+      "dev": true,
       "license": "MIT"
     },
     "node_modules/content-type": {
@@ -4035,9 +4044,9 @@
       "license": "MIT"
     },
     "node_modules/glob/node_modules/brace-expansion": {
-      "version": "2.1.4",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.1.4.tgz",
-      "integrity": "sha512-hGfVzPxthbf3+2yjg/RBs60cB0FhqBS/zvdV/4wn4/BmN0bNMMHPc4V/BbFieqf1TKAGGAHnY4eSjajCl0f2Xg==",
+      "version": "2.1.7",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.1.7.tgz",
+      "integrity": "sha512-uZbew1NqdmPDTMJ8ah1y+b+9QEJrfkXFk3RcTQw3X0jW/xRUvFKsg1CfQdSYGdTbXZWExtU3J3ccxtnfw1Fi0g==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -5241,6 +5250,7 @@
       "version": "3.1.5",
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.5.tgz",
       "integrity": "sha512-VgjWUsnnT6n+NUk6eZq77zeFdpW2LWDzP6zFGrCbHXiYNul5Dzqk2HHQ5uFH2DNW5Xbp8+jVzaeNt94ssEEl4w==",
+      "dev": true,
       "license": "ISC",
       "dependencies": {
         "brace-expansion": "^1.1.7"
@@ -5253,12 +5263,14 @@
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.2.tgz",
       "integrity": "sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==",
+      "dev": true,
       "license": "MIT"
     },
     "node_modules/minimatch/node_modules/brace-expansion": {
-      "version": "1.1.18",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.18.tgz",
-      "integrity": "sha512-Edep/X9fGqVNmzKBVsDYIOtD+z1tuezV70LBjdCst9Tqu76lsnvRiZ6oTic1n+/BIwX6QDGAO94PN4N2SADvtw==",
+      "version": "1.1.21",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.21.tgz",
+      "integrity": "sha512-9zeA+KLZNNzglF2TPKRQEDyx6Yby7daAkuy8MiPzpXPsYDWi/DRM8jmwUDxokQjYqBpv5DgPiwD4h4ZZSy1Ujw==",
+      "dev": true,
       "license": "MIT",
       "dependencies": {
         "balanced-match": "^1.0.0",
@@ -6366,9 +6378,9 @@
       }
     },
     "node_modules/undici": {
-      "version": "6.28.0",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-6.28.0.tgz",
-      "integrity": "sha512-LIY910g9TI13YS95lrMFrs8Rm/u/irgHeTWoKCoteeJ04CUJ92eEfj0rVn+7VKMPBpUPiUoBKfhNyLI23EE/KA==",
+      "version": "6.29.1",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-6.29.1.tgz",
+      "integrity": "sha512-EvRlUt/QqAEvXdQeRMYUfwOQsfzpDztykrG2owGEE/rBOBoYv9uF39ZzsNDh4lTFHhTr2XOZjKkYgueD12ZmGA==",
       "license": "MIT",
       "engines": {
         "node": ">=18.17"

package.json

@@ -1,6 +1,6 @@
 {
   "name": "setup-dotnet",
-  "version": "6.0.0",
+  "version": "6.1.0",
   "type": "module",
   "private": true,
   "description": "setup dotnet action",
@@ -30,7 +30,7 @@
   "author": "GitHub",
   "license": "MIT",
   "dependencies": {
-    "@actions/cache": "^6.2.0",
+    "@actions/cache": "^6.3.0",
     "@actions/core": "^3.0.1",
     "@actions/exec": "^3.0.0",
     "@actions/github": "^9.1.1",

src/installer.ts

@@ -7,7 +7,10 @@ import {
   accessSync,
   chmodSync,
   constants as fsConstants,
+  lstatSync,
+  mkdtempSync,
   readdirSync,
+  rmSync,
   statSync
 } from 'fs';
 import path from 'path';
@@ -347,11 +350,97 @@ export abstract class DotnetInstallDir {
     windows: path.join(process.env['PROGRAMFILES'] + '', 'dotnet')
   };
 
-  public static readonly dirPath = process.env['DOTNET_INSTALL_DIR']
-    ? DotnetInstallDir.convertInstallPathToAbsolute(
+  private static resolvedDirPath: string | undefined;
+
+  // Resolved on first use so a job that installs nothing never touches the disk.
+  public static get dirPath(): string {
+    DotnetInstallDir.resolvedDirPath ??= DotnetInstallDir.resolveDirPath();
+    return DotnetInstallDir.resolvedDirPath;
+  }
+
+  private static resolveDirPath(): string {
+    if (process.env['DOTNET_INSTALL_DIR']) {
+      return DotnetInstallDir.convertInstallPathToAbsolute(
         process.env['DOTNET_INSTALL_DIR']
-      )
-    : DotnetInstallDir.default[PLATFORM];
+      );
+    }
+
+    const systemPath = DotnetInstallDir.default[PLATFORM];
+    const homePath = DotnetInstallDir.homeInstallPath();
+
+    // A relative default (unset HOME/PROGRAMFILES) would probe the cwd.
+    if (
+      path.isAbsolute(systemPath) &&
+      DotnetInstallDir.isWritableLocation(systemPath)
+    ) {
+      return systemPath;
+    }
+
+    // On macOS both candidates are the same path, already probed above.
+    const hasFallback = !!homePath && homePath !== systemPath;
+
+    if (hasFallback && DotnetInstallDir.isWritableLocation(homePath!)) {
+      core.warning(
+        `The default .NET install directory '${systemPath}' is not writable by the current user. Falling back to '${homePath}'; .NET preinstalled in the default location will no longer be used. Set the DOTNET_INSTALL_DIR environment variable to override this location.`
+      );
+      return homePath!;
+    }
+
+    // Not setFailed: the install may still succeed, so let it report the error.
+    core.warning(
+      hasFallback
+        ? `Neither the default .NET install directory '${systemPath}' nor '${homePath}' is writable by the current user. Keeping '${systemPath}', but the installation is likely to fail. Set the DOTNET_INSTALL_DIR environment variable to a writable location.`
+        : `The default .NET install directory '${systemPath}' is not writable by the current user. Keeping it, but the installation is likely to fail. Set the DOTNET_INSTALL_DIR environment variable to a writable location.`
+    );
+    return systemPath;
+  }
+
+  private static homeInstallPath(): string | undefined {
+    try {
+      const home = os.homedir();
+      // An empty HOME resolves against the cwd; a root HOME gives '/.dotnet'.
+      if (!path.isAbsolute(home) || home === path.parse(home).root) {
+        return undefined;
+      }
+      return path.join(home, '.dotnet');
+    } catch {
+      return undefined;
+    }
+  }
+
+  // Writability is tested by creating a directory. accessSync is not enough: it
+  // ignores Windows ACLs, so it reports success where the install would fail.
+  private static isWritableLocation(installDir: string): boolean {
+    let existingPath = path.resolve(installDir);
+
+    try {
+      // lstat also matches a broken symlink. existsSync does not, and the walk
+      // would skip past it to a writable parent and wrongly report success.
+      while (!lstatSync(existingPath, {throwIfNoEntry: false})) {
+        const parentPath = path.dirname(existingPath);
+        if (parentPath === existingPath) return false;
+        existingPath = parentPath;
+      }
+    } catch {
+      return false;
+    }
+
+    let probeDir: string | undefined;
+    try {
+      probeDir = mkdtempSync(path.join(existingPath, '.setup-dotnet-probe-'));
+      return true;
+    } catch {
+      return false;
+    } finally {
+      if (probeDir) {
+        try {
+          rmSync(probeDir, {recursive: true, force: true});
+        } catch {
+          // Throwing here would discard the result already returned above.
+        }
+      }
+    }
+  }
 
   private static convertInstallPathToAbsolute(installDir: string): string {
     if (path.isAbsolute(installDir)) return path.normalize(installDir);
@@ -410,10 +499,6 @@ function isExecutableFile(filePath: string): boolean {
 export class DotnetCoreInstaller {
   private static readonly FeatureBandSyntax = /^(\d+)\.(\d+)\.(\d)xx$/;
 
-  static {
-    DotnetInstallDir.setEnvironmentVariable();
-  }
-
   constructor(
     private version: string,
     private quality: QualityOptions,
@@ -421,7 +506,8 @@ export class DotnetCoreInstaller {
     private dotnetChannel?: string,
     private checkLatest: boolean = true,
     private minimumVersion?: string,
-    private rollForward?: string
+    private rollForward?: string,
+    private skipLtsPrepass: boolean = false
   ) {
     this.version = version.trim();
   }
@@ -686,6 +772,9 @@ export class DotnetCoreInstaller {
   }
 
   public async installDotnet(): Promise<string | null> {
+    // Before findLocalSdkVersion(), which looks under the resolved directory.
+    DotnetInstallDir.setEnvironmentVariable();
+
     const isCrossArch =
       !!this.architecture &&
       normalizeArch(this.architecture) !== normalizeArch(os.arch());
@@ -720,29 +809,34 @@ export class DotnetCoreInstaller {
       : [];
     /**
      * Install dotnet runtime first in order to get
-     * the latest stable version of dotnet CLI
+     * the latest stable version of dotnet CLI.
+     * Opt-out via skip-lts-prepass when this safeguard isn't needed.
      */
-    const runtimeInstallOutput = await new DotnetInstallScript()
-      .useArchitecture(this.architecture)
-      // If dotnet CLI is already installed - avoid overwriting it
-      .useArguments(
-        IS_WINDOWS ? '-SkipNonVersionedFiles' : '--skip-non-versioned-files'
-      )
-      // Install only runtime + CLI
-      .useArguments(IS_WINDOWS ? '-Runtime' : '--runtime', 'dotnet')
-      // Use latest stable version
-      .useArguments(IS_WINDOWS ? '-Channel' : '--channel', 'LTS')
-      .useArguments(...architectureArguments)
-      .execute();
+    if (!this.skipLtsPrepass) {
+      const runtimeInstallOutput = await new DotnetInstallScript()
+        .useArchitecture(this.architecture)
+        // If dotnet CLI is already installed - avoid overwriting it
+        .useArguments(
+          IS_WINDOWS ? '-SkipNonVersionedFiles' : '--skip-non-versioned-files'
+        )
+        // Install only runtime + CLI
+        .useArguments(IS_WINDOWS ? '-Runtime' : '--runtime', 'dotnet')
+        // Use latest stable version
+        .useArguments(IS_WINDOWS ? '-Channel' : '--channel', 'LTS')
+        .useArguments(...architectureArguments)
+        .execute();
 
-    if (runtimeInstallOutput.exitCode) {
-      /**
-       * dotnetInstallScript will install CLI and runtime even if previous script haven't succeded,
-       * so at this point it's too early to throw an error
-       */
-      core.warning(
-        `Failed to install dotnet runtime + cli, exit code: ${runtimeInstallOutput.exitCode}. ${runtimeInstallOutput.stderr}`
-      );
+      if (runtimeInstallOutput.exitCode) {
+        /**
+         * dotnetInstallScript will install CLI and runtime even if previous script haven't succeded,
+         * so at this point it's too early to throw an error
+         */
+        core.warning(
+          `Failed to install dotnet runtime + cli, exit code: ${runtimeInstallOutput.exitCode}. ${runtimeInstallOutput.stderr}`
+        );
+      }
+    } else {
+      core.info('Skipping LTS runtime pre-pass (skip-lts-prepass: true).');
     }
 
     /**

src/setup-dotnet.ts

@@ -130,6 +130,8 @@ export async function run() {
         );
       }
 
+      const skipLtsPrepass = core.getBooleanInput('skip-lts-prepass');
+
       let dotnetInstaller: DotnetCoreInstaller;
       const uniqueVersions = new Set<string>(
         versions.map(v => (v.toLowerCase() === 'latest' ? 'latest' : v))
@@ -143,7 +145,8 @@ export async function run() {
           version.toLowerCase() === 'latest' ? dotnetChannel : undefined,
           checkLatest,
           constraint?.minimumVersion,
-          constraint?.rollForward
+          constraint?.rollForward,
+          skipLtsPrepass
         );
         const installedVersion = await dotnetInstaller.installDotnet();
         installedDotnetVersions.push(installedVersion);