The new bin/bats is a wrapper to call the bats frontend:

  exec "${0%/*}/../libexec/bats" "$@"

The $0 in a basher installation and in other installations may be a symlink.
Taking the directory part of the symlink gives the wrong path, so an additional step is needed:

  _0=$(realpath "$0")

which is why perhaps a symlink is better. I see the objective (#32) is to avoid issues with symlinks on windows.

I'd really like to use a packer manager to get basher. basherpm works well for small projects, as long as some common sense rules are followed. Maybe this isn't supported, or maybe there is something better. What is the preferred installation method?