debugging FUSE application

Question

I have a test application which tests my FUSE implementation by accessing the virtual files. The test application creates a subprocess (using fork) where my test is implemented. In the parent process the filesystem is created and handled.

For debugging the test (child) implementation I use the gdb option -gdb-set follow-fork-mode child. So far so good, I can debug both processes and implementations.

When I swap the two processes: Now my test is in the parent and the child contains the filesystem implementation, I observe a issue when debugging the child process. In this case, the call of fuse_mount(..) hangs and no filesystem is setup.

I try to understand the issue and probably the limits of FUSE. Does anyone know the reason, why debugging FUSE in a subprocess isn't possible?

Thanks