The “ResolveLibraryProjectImports” task failed unexpectedly

Question

I have a Xamarin project, which is based on MvvmCross. The project is for both iOS and Android. I opened this project in Visual Studio 15. I got some errors, wh

Answer 1

We have encountered this too, it appears to be some type of race condition when building multiple projects and a very deep/complex dependency tree (our example has over 100 projects).

The only way we've been able to resolve this (beyond continually rebuilding) is to disable Visual Studio 2017's Parallel Build Abilities (Tools->Options->Projects and Solutions->Build and Run->"1" Maximum number of parallel project builds).

The problem appears to be in ResolveLibraryProjectImports.cs (https://github.com/xamarin/xamarin-android/blob/93ddf96f86710ad848d5189858567dd7fe964579/src/Xamarin.Android.Build.Tasks/Tasks/ResolveLibraryProjectImports.cs) there is most likely a race condition with their logic to shorten up the file names.

There are zero tests around this which means there is most likely some dodgy code.

I am going to attempt to dig more and get an issue opened up on GitHub but finding a reliable repo is probably going to be very difficult.