Problem executing custom build rules in parallel inside the VS 2010 IDE

Question

I have a solution with several projects in it that executes many custom build steps. Some projects depend on other projects, but most of the build steps are independent of each other.

When building inside the VS 2010 IDE, I am getting errors like this:

error MSB6003: The specified task executable "cmd.exe" could not be run. The process cannot access the file 'C:\full\path\Debug\custombuild.write.1.tlog' because it is being used by another process

However, when I build the solution with MSBuild from the command line, all is well, and the log file writing does not seem to cause the same error.

Is this a known issue? Google has not been much help today...

Answer 1

The answer was hinted at in an MSBuild forum thread.

The custom build rule logs are written into the containing project's $(IntDir). We had multiple projects (with no real output being sent to IntDir) that all inadvertently shared the same IntDir value. Giving each project its own IntDir value eliminated the problem.