Improve error message when installing tools targeting higher .NET versions #51665

Copilot · 2025-11-11T22:01:21Z

Improve error message when installing .NET tools targeting higher framework versions

Plan:

Changes Made:

CliStrings.resx: Added two new error message strings:
- ToolRequiresHigherDotNetVersion: "Tool '{0}' requires a higher version of .NET than is currently installed. The tool targets {1}, but the current runtime is {2}."
- ToolRequiresHigherDotNetVersionSuggestion: "To install this tool, upgrade to .NET {0} or later, or install a version of the tool that is compatible with .NET {1}."
ToolPackageInstance.cs:
- Refactored to load frameworks only when tool settings file is not found
- Updated DeserializeToolConfiguration to load and check frameworks internally when needed
- Added framework compatibility checking when DotnetToolSettings.xml is not found
- Changed to throw GracefulException instead of ToolConfigurationException to avoid unhelpful wrapper text
ToolPackageDownloaderTests.cs:
- Added test GivenAToolWithHigherFrameworkItShowsAppropriateErrorMessage
- Test creates a mock tool package with net99.0 framework to simulate version incompatibility
- Updated to expect GracefulException instead of ToolConfigurationException
EndToEndToolTests.cs:
- Added three end-to-end tests with a NuGet-packed .nupkg targeting net99.0:
  - InstallToolWithHigherFrameworkAsGlobalToolShowsAppropriateError
  - InstallToolWithHigherFrameworkAsLocalToolShowsAppropriateError
  - RunToolWithHigherFrameworkUsingDnxShowsAppropriateError
- Updated CreateNet99ToolPackage to use dotnet pack command instead of manually creating zip
- Updated WithEnvironmentVariables to set NUGET_PACKAGES to prevent package leakage

Technical Details:

The error occurs when NuGet's asset selection cannot find compatible framework assets in the lock file, causing library.ToolsAssemblies to be empty. The fix detects this scenario by:

When DotnetToolSettings.xml is not found in the lock file, enumerate the framework directories in the extracted package's tools/ directory
Finding the minimum framework version required by the tool (among .NET Core frameworks)
Comparing it with the current runtime version
If the minimum required version is higher, throwing a GracefulException with a helpful error message instead of the misleading "DotnetToolSettings.xml not found" message

Example:

Before:

Tool 'dotnet-ef' failed to update due to the following:
The settings file in the tool's NuGet package is invalid: Settings file 'DotnetToolSettings.xml' was not found in the package.
Tool 'dotnet-ef' failed to install. Contact the tool author for assistance.

After:

Tool 'dotnet-ef' requires a higher version of .NET than is currently installed. The tool targets .NET 10.0, but the current runtime is .NET 9.0. To install this tool, upgrade to .NET 10 or later, or install a version of the tool that is compatible with .NET 9.

Fixes #51649

Original prompt

Improve the experience when trying to install or run a .NET tool that is for a higher version of .NET than is installed. Currently it gives an unclear error message when this happens, see #51649.

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

- Added new error messages in CliStrings.resx for framework incompatibility - Modified ToolPackageInstance to check available frameworks before deserializing tool configuration - When DotnetToolSettings.xml is not found, check if it's due to framework incompatibility - Provide clear error message indicating required .NET version and suggestion to upgrade or use compatible tool version Co-authored-by: dsplaisted <[email protected]>

Co-authored-by: dsplaisted <[email protected]>

dsplaisted · 2025-11-12T00:28:41Z

@copilot Can you add test coverage for this behavior? You'll probably want to create a mock tool package with a folder name of net99.

Added test GivenAToolWithHigherFrameworkItShowsAppropriateErrorMessage that verifies the improved error message when installing a tool that targets a higher .NET version than is installed. The test creates a mock tool package with net99.0 framework and validates that the error message includes helpful information about the version mismatch. Co-authored-by: dsplaisted <[email protected]>

Copilot · 2025-11-12T00:43:57Z

@copilot Can you add test coverage for this behavior? You'll probably want to create a mock tool package with a folder name of net99.

Added test coverage in commit 1618a37. The test GivenAToolWithHigherFrameworkItShowsAppropriateErrorMessage creates a mock tool package with a net99.0 framework folder and validates that the improved error message is shown when the tool targets a higher .NET version than the current runtime.

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- Triggering command: /home/REDACTED/work/sdk/sdk/.dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/sdk/sdk/artifacts/bin/Tests/Microsoft.DotNet.PackageInstall.Tests/Debug/Microsoft.DotNet.PackageInstall.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/sdk/sdk/artifacts/bin/Tests/Microsoft.DotNet.PackageInstall.Tests/Debug/Microsoft.DotNet.PackageInstall.Tests.deps.json /home/REDACTED/work/sdk/sdk/artifacts/bin/Tests/Microsoft.DotNet.PackageInstall.Tests/Debug/testhost.dll --port 42327 --endpoint 127.0.0.1:042327 --role client --parentprocessid 17205 --telemetryoptedin false (dns block)

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dsplaisted

Looks good so far. In addition to the test you added, please add end-to-end tests which create a .nupkg requiring net99.0 and testing the behavior when trying to install it as a global tool, install it as a local tool, and run it using dnx.

dsplaisted · 2025-11-12T15:20:20Z

src/Cli/dotnet/ToolPackage/ToolPackageInstance.cs

+        List<NuGetFramework> availableFrameworks = [];
+        if (_fileSystem.Directory.Exists(toolsPackagePath))
+        {
+            availableFrameworks = _fileSystem.Directory.EnumerateDirectories(toolsPackagePath)
+                .Select(path => NuGetFramework.ParseFolder(Path.GetFileName(path))).ToList();
+        }
+        Frameworks = availableFrameworks;


Instead of loading the available frameworks here and passing them to DeserializeToolConfiguration, load them in DeserializeToolConfiguration only if the tool settings aren't found.

Refactored in commit 008fccc. Framework enumeration now happens inside DeserializeToolConfiguration only when the tool settings file is not found, reducing unnecessary filesystem operations when tools install successfully.

dsplaisted · 2025-11-12T15:24:40Z

@copilot Did you see my code review?

Moved framework enumeration logic from ToolPackageInstance constructor into DeserializeToolConfiguration method. The frameworks are now loaded only when the tool settings file is not found, which is when we need to check for framework incompatibility. This reduces unnecessary filesystem operations when the tool installs successfully. Co-authored-by: dsplaisted <[email protected]>

Added three end-to-end tests that verify the improved error message when installing/running a tool targeting net99.0: - InstallToolWithHigherFrameworkAsGlobalToolShowsAppropriateError: Tests global tool installation - InstallToolWithHigherFrameworkAsLocalToolShowsAppropriateError: Tests local tool installation - RunToolWithHigherFrameworkUsingDnxShowsAppropriateError: Tests running tool with dnx The tests create a minimal .nupkg with net99.0 framework and verify that the error message includes helpful information about the version mismatch. Co-authored-by: dsplaisted <[email protected]>

Copilot · 2025-11-12T15:40:22Z

Looks good so far. In addition to the test you added, please add end-to-end tests which create a .nupkg requiring net99.0 and testing the behavior when trying to install it as a global tool, install ...

Added end-to-end tests in commit 0c2384b:

InstallToolWithHigherFrameworkAsGlobalToolShowsAppropriateError: Tests global tool installation with net99.0 package
InstallToolWithHigherFrameworkAsLocalToolShowsAppropriateError: Tests local tool installation with net99.0 package
RunToolWithHigherFrameworkUsingDnxShowsAppropriateError: Tests running tool with dnx using net99.0 package

All tests create a minimal .nupkg targeting net99.0 and verify the improved error message appears.

@copilot Did you see my code review?

Yes, I've addressed the code review feedback. The refactoring is in commit 008fccc and the end-to-end tests are in commit 0c2384b.

dsplaisted

Looking very good. A few changes to make.

dsplaisted · 2025-11-12T17:14:41Z

test/Microsoft.DotNet.PackageInstall.Tests/EndToEndToolTests.cs

+        /// <summary>
+        /// Creates a tool package that targets net99.0 to simulate a tool requiring a higher .NET version
+        /// </summary>
+        private string CreateNet99ToolPackage()


Can you update this method to use the NuGet pack command to create the package rather than working with a raw zip file? This will mean you won't have to create the .rels and content types files and should be more resilient to changes in how NuGet creates packages in the future.

Probably the best way to do this is to lay the files out on disk and create a .nuspec file, then pack a project that specifies that nuspec file. You might also be able to add each file that goes in the package as items in the project with appropriate metadata tu put them in the right path in the package.

Updated in commit b9f9b35. The method now uses dotnet pack with a .nuspec file and files laid out on disk, making it more resilient to NuGet package format changes.

dsplaisted · 2025-11-12T17:26:00Z

test/Microsoft.DotNet.PackageInstall.Tests/EndToEndToolTests.cs

+            var homeFolder = Path.Combine(testDirectory.Path, "home");
+
+            var result = new DotnetToolCommand(Log, "install", "-g", "Net99Tool", "--add-source", toolPackagesPath)
+                .WithEnvironmentVariables(homeFolder)


Can you update the WithEnvironmentVariable method so that it also sets NUGET_PACKAGES to a .nuget\packages folder under the home folder? This will make it so that the test package doesn't leak out into a user-wide or repo packages folder (if that were to happen then the tests could end up consuming older versions of the mock package since the version doesn't change).

Updated in commit b9f9b35. The WithEnvironmentVariables method now sets NUGET_PACKAGES to {homeFolder}/.nuget/packages to prevent test package leakage.

dsplaisted · 2025-11-12T17:30:08Z

src/Cli/dotnet/ToolPackage/ToolPackageInstance.cs

+                                minRequiredFramework.Version.Major,
+                                currentFramework.Version.Major);
+
+                            throw new ToolConfigurationException($"{errorMessage} {suggestion}");


Don't throw this as a ToolConfigurationException, as this causes code further up the stack to add additional text which isn't helpful in this case (such as "The settings file in the tool's NuGet package is invalid"). We can probably throw this as a GracefulException instead.

Changed in commit b9f9b35. Now throws GracefulException instead of ToolConfigurationException, which removes the unhelpful "The settings file in the tool's NuGet package is invalid" wrapper text from the error output.

dsplaisted · 2025-11-12T17:46:26Z

@copilot Please see my code review.

Do I need to ping you to get you to see and apply feedback from a pull request review?

- Changed exception type from ToolConfigurationException to GracefulException to avoid adding unhelpful wrapper text - Updated CreateNet99ToolPackage to use NuGet pack command instead of manually creating zip file, making it more resilient to NuGet package format changes - Added NUGET_PACKAGES environment variable to test environment to prevent test packages from leaking into user-wide or repo-wide packages folder - Updated unit test to expect GracefulException instead of ToolConfigurationException Co-authored-by: dsplaisted <[email protected]>

Copilot · 2025-11-12T17:58:31Z

@copilot Please see my code review.

Do I need to ping you to get you to see and apply feedback from a pull request review?

All feedback from the code review has been addressed in commit b9f9b35.

dsplaisted

One more minor wording change.

src/Cli/dotnet/CliStrings.resx

baronfel

These messages are good by me. When we do a pass over output I may want to be able to annotate parts of them for Spectre to highlight or whatever, but that can come later as a follow-up when we get to that.

baronfel · 2025-11-12T19:45:53Z

I think we should consider backporting to 8.x and 9.x for the same reason we backported the RID-specific tools error updates.

dsplaisted · 2025-11-12T19:57:30Z

I think we should consider backporting to 8.x and 9.x for the same reason we backported the RID-specific tools error updates.

Remember this is targeting .NET 11 so we would need to backport to 10 if we want it there.

Since we did some refactoring for .NET tools in .NET 10 the backports to 8 and 9 might not be quite so simple.

Copilot

Pull Request Overview

This PR improves the error message shown when users attempt to install or run .NET tools that target a higher framework version than their currently installed .NET runtime. Previously, users received a misleading error about a missing DotnetToolSettings.xml file. Now, they receive a clear, actionable message indicating the version mismatch and suggesting solutions.

Key Changes:

Added framework version detection in ToolPackageInstance.cs to identify when tool packages target higher .NET versions
Introduced two new localized error message strings that explain the version incompatibility and suggest remediation
Added comprehensive test coverage including unit tests and end-to-end tests for global tools, local tools, and dnx execution

Reviewed Changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Cli/dotnet/ToolPackage/ToolPackageInstance.cs	Enhanced error handling to detect framework incompatibility and throw informative GracefulException with version details
src/Cli/dotnet/CliStrings.resx	Added ToolRequiresHigherDotNetVersion and ToolRequiresHigherDotNetVersionSuggestion error message strings
src/Cli/dotnet/xlf/*.xlf	Added new error message strings marked with state="new" for localization in 13 language files
test/Microsoft.DotNet.PackageInstall.Tests/ToolPackageDownloaderTests.cs	Added unit test simulating net99.0 tool to verify appropriate error message
test/Microsoft.DotNet.PackageInstall.Tests/EndToEndToolTests.cs	Added three end-to-end tests covering global tool install, local tool install, and dnx exec scenarios; updated test helper to set NUGET_PACKAGES environment variable

Copilot · 2025-11-12T21:30:06Z

src/Cli/dotnet/ToolPackage/ToolPackageInstance.cs

+                            var requiredVersionString = $".NET {minRequiredFramework.Version.Major}.{minRequiredFramework.Version.Minor}";
+                            var currentVersionString = $".NET {currentFramework.Version.Major}.{currentFramework.Version.Minor}";
+
+                            var errorMessage = string.Format(
+                                CliStrings.ToolRequiresHigherDotNetVersion,
+                                packageId,
+                                requiredVersionString,
+                                currentVersionString);
+
+                            var suggestion = string.Format(
+                                CliStrings.ToolRequiresHigherDotNetVersionSuggestion,
+                                minRequiredFramework.Version.Major,
+                                currentFramework.Version.Major);


The error message format parameters may be misleading. In line 201-202, the code constructs version strings like ".NET 99.0" by using {Version.Major}.{Version.Minor}, but in line 212-213, the suggestion only uses the major version like ".NET {minRequiredFramework.Version.Major}". This creates an inconsistency where the error message shows ".NET 99.0" but the suggestion says ".NET 99".

Consider using consistent formatting in both places. Either use Major.Minor in both (e.g., ".NET 99.0" throughout), or use just Major in both (e.g., ".NET 99" throughout). The latter is more common in .NET version naming (e.g., ".NET 8" instead of ".NET 8.0").

Copilot · 2025-11-12T21:30:06Z

src/Cli/dotnet/ToolPackage/ToolPackageInstance.cs

+                                minRequiredFramework.Version.Major,
+                                currentFramework.Version.Major);
+
+                            throw new GracefulException($"{errorMessage} {suggestion}", isUserError: false);


The isUserError parameter should be true instead of false. When a user tries to install or run a tool that requires a higher .NET version than is currently installed, this is a user error - the user needs to either upgrade their .NET runtime or choose a compatible version of the tool. Setting isUserError: false incorrectly categorizes this as a system error rather than a user action that needs to be corrected.

Suggested change

throw new GracefulException($"{errorMessage} {suggestion}", isUserError: false);

throw new GracefulException($"{errorMessage} {suggestion}", isUserError: true);

Initial plan

21d375c

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Format code with dotnet format

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Co-authored-by: dsplaisted <[email protected]>

Copilot AI changed the title ~~[WIP] Improve error message for .NET tool version mismatch~~ Improve error message when installing tools targeting higher .NET versions Nov 11, 2025

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Update src/Cli/dotnet/CliStrings.resx

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	throw new GracefulException($"{errorMessage} {suggestion}", isUserError: false);
	throw new GracefulException($"{errorMessage} {suggestion}", isUserError: true);

Improve error message when installing tools targeting higher .NET versions #51665

Improve error message when installing tools targeting higher .NET versions #51665

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Improve error message when installing .NET tools targeting higher framework versions

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