Why does C#/MSBuild spontaneously use a different output path for different projects?

Question

When I have a C# console application foo, and I compile it with

msbuild /p:Configuration=Debug /p:Platform="Any CPU"

Sometimes the resulting executable is

bin\Any CPU\Debug\net7.0\foo.exe" 

and sometimes

bin\Debug\net7.0\foo.exe

Why?

Note:

• There is no OutputPath element in any of the project files.

• I am not asking how to change the behavior, but why it is currently as it is.

Answer 1

Thanks to Sir Rufo for https://github.com/dotnet/sdk/issues/10188 which turned out to be the clue to the answer: it depends on whether MSBuild is working from a .sln or .csproj file. It defaults to the former if present, which means it produces different results for a single-project solution with both files in the same directory, versus a multi-project solution.