I am working on a solution consisting of 8 .NET projects. Since I am practicing TDD, I have to re-compile my solution very often. Lately I have been getting the following error about every second time when trying to compile:
Error 2 Unable to copy file
“obj\Debug\Zeiterfassung.Tests.dll” to
“bin\Debug\Zeiterfassung.Tests.dll”.
The process cannot access the file
‘bin\Debug\Zeiterfassung.Tests.dll’
because it is being used by another
process.
Zeiterfassung.Tests.dll is the dll generated by one of my projects (it’s the unit testing project). It’s always this dll that cannot be copied and causes the error. Everything else works fine 100% of the time.
In about 9/10 times I can “solve” the problem by recompiling my solution again. But when the problem is getting really bad, the project just won’t compile successfully no matter how often I try and I have to restart the IDE.
I used microsoft’s handle.exe to ascertain which process is locking the DLL and it is devenv.exe. I also tried deleting the DLL by hand and it really can’t be deleted until I restart the IDE.
Last but not least, I tried adding <GenerateResourceNeverLockTypeAssemblies>true</GenerateResourceNeverLockTypeAssemblies> to my project as suggested in another forum, but this did not help.
Please help! This problem is really starting to drive me nuts.
Edit: I might also add that I made sure my unit tests are finished when this problem occurrs. Still, the dll remains locked. I am running my tests via the Resharper unit test explorer.
Looks like the bug disappeared (fingers crossed…) after I moved my test project, checked out an earlier version of the project from the repository and replaced all code files with the newer versions.