If I have an issue about one certain package, how should I submit an issue about it?
The reason why I ask this question is that nixos contains a large amount of packages, and any one package is just a tiny piece of the whole system. If I submit an issue about one of them to github, it may be submerge by others.
You should submit it on the github issue tracker (with the package name
in the subject) and ping the maintainer(s) of the package.
Yes, it is imperfect, but it is the best we have until we move to a
proper issue tracker, which doesn’t appear to be coming any time soon.
If you’re able and willing to help out on the issue yourself you can usually get some good help from either IRC or within the github issue itself. If the issue remains unanswered bring it up on discourse and ask for help.