$ git clone -n https://src.fedoraproject.org/rpms/composer.git /var/lib/mock/f42-build-side-1-3537704-46560/root/chroot_tmpdir/scmroot/composer
Cloning into '/var/lib/mock/f42-build-side-1-3537704-46560/root/chroot_tmpdir/scmroot/composer'...
$ git fetch origin 37302d9faf98badd8a872f4487365fab89e66f76:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/composer
 * [new ref]         37302d9faf98badd8a872f4487365fab89e66f76 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 37302d9 v2.8.9