Visual studio build fails while copying files to the bin directory due to file locks by vmwp.exe

Question

I'm running my development environment in Docker containers. Since I have done some updates I'm now experiencing some difficulties when trying to rebuild my project that's running in my Docker container.

My project is running in a Windows Server Core Docker container running IIS, and I'm running the project from a shared volume on my host. I'm able to build the project before starting the docker container, but after the docker container is started the build fails with the following error:

Could not copy "C:\path\to\dll\name.dll" to "bin\name.dll". Exceeded retry count of 10. Failed. The file is locked by: "vmwp.exe (22604), vmmem (10488)"

It seems that the Hyper-V process is locking the DLL files. This clearly wasn't the case before and this seems to be related to some Docker or Windows updates I have done. How can I solve this issue? Do I need to change the process of building the application and running it in my Docker containers?

I have been searching for a while now, and I can't find much about this specific issue. Any help would be appreciated. Thanks in advance!

Answer 1

I've run in the similar problem. Solved by stopping/removing the running application container from docker-for-windows interface. docker rm -f will also do.

Answer 2

1. If you use Docker Windows Containers make sure you have at least Windows 10.0.1809 on both environment(your physical machine and on docker) -run CMDs and you will see on top of it.
2. Use isolation flag with process when you run docker: --isolation process.

On physical machine two vmxxx(lower and higher PID)(don't remember the name exactly) processes was keeping *.dll file(the build was going on docker side where build tools 2019 was used).

Potential solution:

1. First MSbuild Error occurred because msbuild tries to delete file - access denied - probably this one vm process handle the file.
2. Second Msbuild Error occurred(the first vmxxx one caused that) showing that copy file from one direction to another it's not possible due to System lock (4).

Both vmxxx processes keeping those two dll files during build on docker. One vmxxx had higher number of PID and second had lower number of PID.

Isolation should take care of processes when you build project from docker container.