hpc mix files for Main modules overwrite each other

[guest]

I have several programs, and hence several files that define Main modules, in the same directory. I build each one with a ghc --make -o Progname. When The hpc mix files describing the compiled modules are dumped in .hpc, the current Main.mix overwrites any previous Main.mix. As a result, I can only get an hpc report from Progname.tix if Progname was the most recent binary to be compiled.