qt install path differs by linux distro (and by OS)

[justbuchanan]

In order to use bazel_rules_qt in a bazel project, this must be added to the WORKSPACE fiile:

git_repository(
    name = "com_justbuchanan_rules_qt",
    remote = "https://github.com/justbuchanan/bazel_rules_qt",
    branch = "master",
    path = "QT_PATH",
)

On debian, QT_PATH should be "/usr/include/x86_64-linux-gnu/qt5" and on arch linux, QT_PATH is "/usr/include/qt". It's unfortunate that the WORKSPACE file must be modified depending on which system you're trying to build your app on. It would be nice to have bazel auto-detect this somehow.

[limdor]

@justbuchanan In case you are interested, I started working on a way to autodetect the system limdor#6, next step will be to read it from an environment variable limdor#13

[justbuchanan]

That looks great! I have a project that I develop on a debian computer and an acrh linux computer, so being able to set QT_DIR and have it just work would be awesome (previously I was editing WORKSPACE). Especially nice that the repository_ctx approach easily adapts to use on windows.