`lib.getExe` and `lib.getExe'` are not safe

[samuela]

@ElvishJerricco

what @samuela is trying to achieve is an eval-time way to get the correct exe name. e.g. if a package named foo has an exe that is not named foo but instead named bar and the package does not include a meta.mainProgram attribute, then the derivation should be built, and it should eval the necessary readDir calls to find a suitable exe name

Almost… what I’m actually after is a way to pick any executable out of a drv’s /bin/, but have it checked at build time that this executable actually exists so as to prevent typos.

[abathur]

Did pbsds’s suggestion satisfy it? If not (and since it sounds like there’s some confusion), maybe a real example of where you want to plug something like this in would help?