[Known Build Error] RunFileTests csc-only mode fails expecting binary log warning that is not emitted

[jkoritzinsky]

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1378681
Build error leg or test failing: dotnet.Tests.dll.20, dotnet.Tests.dll.21, dotnet.Tests.dll.11
Pull request: #53635

Error Message

{
  "ErrorMessage": "Binary log option was specified but MSBuild will be skipped because running just csc is enough",
  "ErrorPattern": "",
  "BuildRetry": true,
  "ExcludeConsoleLog": false
}

Details

Multiple dotnet run file-mode tests that use cscOnly: True with -bl fail because they expect the output to contain the warning:

Warning: Binary log option was specified but MSBuild will be skipped because running just csc is enough. Specify '--no-cache' to force full build.

But the warning is not emitted, causing assertion failures.

Affected tests:

• Microsoft.DotNet.Cli.Run.Tests.RunFileTests_BuildOptions.WorkingDirectory(cscOnly: True)
• Microsoft.DotNet.Cli.Run.Tests.RunFileTests_CscOnlyAndApi.CscOnly
• Microsoft.DotNet.Cli.Run.Tests.RunFileTests_BuildCommands.LaunchProfile(cscOnly: True, relativePath: "Properties/launchSettings.json")

Reproduces on main — confirmed in builds:

• https://dev.azure.com/dnceng-public/public/_build/results?buildId=1377208 (dotnet.Tests.dll.21)
• https://dev.azure.com/dnceng-public/public/_build/results?buildId=1378681 (dotnet.Tests.dll.20, dotnet.Tests.dll.11)

Sample error (WorkingDirectory test):

Expected string to be the same string because Command did not output with Expected Output.
Expected: Warning: Binary log option was specified but MSBuild will be skipped because running just csc is enough. Specify '--no-cache' to force full build.
v1

Sample error (LaunchProfile test):

Expected string "Using launch settings from ...\launchSettings.json...
Hello from Program
Message: 'TestProfileMessage1'" to contain "Warning: Binary log option was specified but MSBuild will be skipped because running just csc is enough. Specify '--no-cache' to force full build.

Sample logs:

• https://helix.dot.net/api/2019-06-17/jobs/2ec4a69a-ca65-403a-a121-f2ee8955290c/workitems/dotnet.Tests.dll.20/console
• https://helix.dot.net/api/2019-06-17/jobs/95b6731c-3af3-41d6-a28a-4409e3901531/workitems/dotnet.Tests.dll.21/console
• https://helix.dot.net/api/2019-06-17/jobs/a39ba85f-6a9c-4f17-9a74-0371ae3aae14/workitems/dotnet.Tests.dll.11/console

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1378681
Error message validated: [Binary log option was specified but MSBuild will be skipped because running just csc is enough]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 4/14/2026 9:13:57 PM UTC

Report

Build	Definition	Test	Pull Request
1378978	dotnet/sdk	Microsoft.DotNet.Cli.Run.Tests.RunFileTests_BuildCommands.LaunchProfile	#53867
1378902	dotnet/sdk	Microsoft.DotNet.Cli.Run.Tests.RunFileTests_BuildOptions.WorkingDirectory	#53680
1378681	dotnet/sdk	Microsoft.DotNet.Cli.Run.Tests.RunFileTests_CscOnlyAndApi.CscOnly	#53635

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
3	3	3