The script wrote the hook to .git/hooks, which fails when .git is a
file rather than a directory, as in a clone made with
--separate-git-dir. It now asks git for the repository's own git
directory with `git rev-parse --git-common-dir`, creates its hooks
directory if missing, and writes the hook there. In an ordinary clone
that is .git/hooks, so nothing moves. git's core.hooksPath setting is
not followed, so the script never writes outside the repository; where
that setting is in force, git does not run the installed hook, as
before.
Model: opus-5-5
sneak