cabal exec not able to find executable by relative path

[abooij]

cabal exec is not able to find executables in the same directory as the project.

$ vim test.c   # write a hello world executable
$ cabal sandbox init
$ cabal install   # unrelated project
$ gcc -o hello_world test.c
$ ./hello_world
Hello world!
$ cabal exec ./hello_world
cabal: The program './hello_world' is required but it could not be found.
$ cabal exec $(pwd)/hello_world
Hello world!

[ezyang]

Not entirely obvious how to fix. The problem is that cabal-install/Distribution/Client/Exec.hs uses ProgramDb to configure the passed in program, but we assume that the input is the name of the program e.g., gcc, not /abs/path/to/exe); we only look for the program in the path

So I guess what you want to do is detect if a PATH is specified (takeBaseName fp /= fp) and then if that is the case, override programFindLocation to just return the exact path (you'd modify simpleProgram exe in requireProgram'). I don't know if there is a more generalizable lesson we can apply to the API here. @abooij would you like to tackle this one?

P.S. The reason we use the program db in the first place is so you can say cabal exec gcc and it will automatically use the correct gcc that was configured previously. That's useful.

[abooij]

@ezyang, I'd rather not - I just ran into it and thought I'd report it.

[ezyang]

OK, into the triage bin it goes ;)