[BuildCheck Suggestion]: Custom BuildCheck reports are not following the canonical error format

[baronfel]

Summary

Custom BuildChecks that report errors don't seem to be emitting with the canonical error format, leading to GitHub Actions not catching the results as expected.

In this build pipeline, @YuliiaKovalova's custom build check detected the following violation and reported it as an error:

/usr/share/dotnet/sdk/9.0.100-rc.2.24474.11/Current/Microsoft.Common.props(84,119): error BCC002: https://aka.ms/buildcheck/codes#BCC002 - Detected secret: Username with value: 'runner'

In this pipeline the same check reported as a warning and was caught:

/usr/share/dotnet/sdk/9.0.100-rc.2.24474.11/Current/Microsoft.Common.props(84,119): warning BCC002: https://aka.ms/buildcheck/codes#BCC002 - Detected secret: Username with value: 'runner' [/home/runner/work/sdk-container-demo/sdk-container-demo/src/sdk-container-demo/sdk-container-demo.csproj]

The gap seems to be that the final project in the square brackets is missing from the error report.

Background and Motivation

See above

Sample issue or antipattern that the check should be flagging

See above

Sample output

No response