$ git clone -n https://src.fedoraproject.org/rpms/fish.git /var/lib/mock/f42-build-side-1-3541491-46580/root/chroot_tmpdir/scmroot/fish
Cloning into '/var/lib/mock/f42-build-side-1-3541491-46580/root/chroot_tmpdir/scmroot/fish'...
$ git fetch origin 7bffe3f8ff711273c108b473e84361127a439985:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fish
 * [new ref]         7bffe3f8ff711273c108b473e84361127a439985 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7bffe3f Update to 4.0.2 upstream release