pleasew: config files resolved from $PWD instead of pleasew script directory

[simonfxr]

When pleasew is invoked from a path other than the repo root (e.g., ../repo/pleasew or /absolute/path/to/pleasew), it fails to find .plzconfig because it looks in $PWD rather than the directory where pleasew is located.

For me this looks like a bug.

It would be more sensible to do something like this instead:

PLZCONFDIR="$(dirname "$0")"
CONFIGS="$(cat <<- EOS
    ${PLZCONFDIR}/.plzconfig.local
    ${PROFILE:+${PLZCONFDIR}/.plzconfig.${PROFILE}}
    ${PLZCONFDIR}/.plzconfig_${OS}_${ARCH}
    ${PLZCONFDIR}/.plzconfig
    ${HOME}/.config/please/plzconfig
    /etc/please/plzconfig
EOS
)"

[toastwaffle]

There's no guarantee or requirement that pleasew is actually in the Please repository root - we previously had pleasew installed as the plz "binary" on the system path, although we have now replaced that with please_shim.

What it should do is replicate the behaviour of getRepoRoot here - start in the current working directory and traverse upwards until it finds a .plzconfig file. There is also a MustFindRepoRoot() which will look for a WORKSPACE file for bazel compatibility, but I don't think pleasew needs to support that. Would you like to send us a PR to implement that?

[simonfxr]

@toastwaffle Okay sounds sensible to me, please take a look at my PR.