multiple rules generated for ccomp #9225
Description
Watch mode in the dune repo produces this:
Error: Multiple rules generated for _build/default/.dune/ccomp/ccomp:
- <internal location>
- <internal location>
-> required by _build/default/otherlibs/dune-rpc-lwt/test/realpath_stubs.o
-> required by alias otherlibs/dune-rpc-lwt/test/check
This is similar to #9213.