Issue: During VSTS agent build, you encounter errors similar to this one. Most likely during builds involving Fody:
Error: Fody: An unhandled exception occurred:
Exception:
Out of memory
Cause: This appears to be a bug related with Mono/Cecil/Fody
Solution: The current solution is to change Visual Studio for Mac or Xamarin's preference > .NET Runtimes default to "Mono 4.8.0." Please contact our support so we can carry out the setting change for you.
Reference:
Out of Memory in Xamarin Studio and Visual Studio for Mac - Github Forty Issues