Project dependencies built recursively multiple times when using MSBuild command line

Given the following scenario:

Project C depends on Project B

Project B depends on Project A

All projects are QtMsBuild projects.

Building this in Visual Studio 2019 works fine. However, when building this with the command line, with MSBuild.exe, it results in the following build order:

• Project A
• Project A
• Project B
• Project A
• Project B
• Project C

It seems that for each individual project that has to be built, its dependencies are also built. This result in dependencies being built multiple times. When projects have post-build steps, this can result in very long build times.

This also creates problems when using the multi thread switch of MSBuild; some projects seem to get built by multiple threads at the same time, creating a lot of file access issues.

I have attached a solution that exhibits this issue. When building with the command line

msbuild QtTestApp.sln

, we see the following in the output:

Line 41:   QtProjectA.vcxproj -> C:\Code\QtTestAppIssue\Win32\Debug\QtProjectA.dll
Line 66:   QtProjectA.vcxproj -> C:\Code\QtTestAppIssue\Win32\Debug\QtProjectA.dll
Line 86:   QtProjectB.vcxproj -> C:\Code\QtTestAppIssue\Win32\Debug\QtProjectB.dll
Line 120:   QtProjectA.vcxproj -> C:\Code\QtTestAppIssue\Win32\Debug\QtProjectA.dll
Line 139:   QtProjectB.vcxproj -> C:\Code\QtTestAppIssue\Win32\Debug\QtProjectB.dll
Line 180:   QtTestApp.vcxproj -> C:\Code\QtTestAppIssue\Win32\Debug\QtTestApp.exe