No logs (other than binlogs) when building source-build-externals in source-build mode fails

I was making some changes to source-build externals. I then tried to build it:

```
$ ./build.sh --sourceBuild --verbosity detailed
Build failed with errors (9.3s)
/home/omajid/.nuget/packages/microsoft.dotnet.arcade.sdk/9.0.0-beta.24151.5/tools/SourceBuild/SourceBuildArcadeBuild.targets(215,5): error MSB3073: The command "/home/omajid/devel/dotnet/source-build-externals/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:detailed /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/omajid/.nuget/packages/microsoft.dotnet.arcade.sdk/9.0.0-beta.24151.5/tools/Build.proj /p:Configuration=Release /p:RepoRoot=/home/omajid/devel/dotnet/source-build-externals/ /p:Restore=true /p:Build=true /p:DotNetBuildRepo=true /p:ArcadeBuildFromSource=true /p:DotNetBuildSourceOnly=true /p:ArcadeBuildVertical=false /p:Rebuild=false /p:Test=false /p:Pack=true /p:IntegrationTest=false /p:PerformanceTest=false /p:Sign=false /p:Publish=false /v:detailed /p:DotNetBuildInnerRepo=true /p:DotNetBuildSourceOnly=true /p:ArcadeInnerBuildFromSource=true /p:DotNetBuildFromSource=true /p:RepoRoot="/home/omajid/devel/dotnet/source-build-externals/artifacts/sb/src/" /p:ArtifactsDir="/home/omajid/devel/dotnet/source-build-externals/artifacts/sb/src/artifacts/" /bl:"/home/omajid/devel/dotnet/source-build-externals/artifacts/sb/src/artifacts/log/Release/source-inner-build.binlog" /v:detailed /p:SourceBuildOutputDir="/home/omajid/devel/dotnet/source-build-externals/artifacts/sb/" /p:FullAssemblySigningSupported=false" exited with code 1. [/home/omajid/.nuget/packages/microsoft.dotnet.arcade.sdk/9.0.0-beta.24151.5/tools/Build.proj]

Build failed with errors in 9.4s
Build failed with exit code 1. Check errors above.
```

Is there a way to find a log when this happens? I can see the binlog, but no logs with any hints on what went wrong.

Building in non-source-build mode showed me an error message, which pointed me to where I had introduced a build error.