$ git clone -n https://src.fedoraproject.org/rpms/fatcat.git /var/lib/mock/f40-build-799087-142138/root/chroot_tmpdir/scmroot/fatcat
Cloning into '/var/lib/mock/f40-build-799087-142138/root/chroot_tmpdir/scmroot/fatcat'...
$ git fetch origin 122ff543565e3b9bc54b3c45e7755040f419a6af:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fatcat
 * [new ref]         122ff543565e3b9bc54b3c45e7755040f419a6af -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 122ff54 Update to 1.1.1 and fix FTBFS