Errors when processing multiple assemblies with inter-dependencies

[roji]

Unhandled Exception: System.AggregateException: One or more errors occurred. ---> System.IO.IOException: The process
cannot access the file 'C:\temp2\st\xxx.dll' because it is being used by another process.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.File.InternalDelete(String path, Boolean checkHost)
at Daemaged.GitInfoPlanter.program.patchAssembly(String sourceAsm, String destAsm, String gitInfo, Dictionary`2 me
tadata)
at System.Threading.Tasks.Task.Execute()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.WaitAll(Task[] tasks, Int32 millisecondsTimeout, CancellationToken cancellationToke
n)
at System.Threading.Tasks.Task.WaitAll(Task[] tasks, Int32 millisecondsTimeout)
at System.Threading.Tasks.Task.WaitAll(Task[] tasks)
at Daemaged.GitInfoPlanter.program.main(String[] args)