$ git clone -n https://src.fedoraproject.org/rpms/php-pecl-yac.git /var/lib/mock/f42-build-862859-171186/root/chroot_tmpdir/scmroot/php-pecl-yac
Cloning into '/var/lib/mock/f42-build-862859-171186/root/chroot_tmpdir/scmroot/php-pecl-yac'...
$ git fetch origin 69768b522eb04f709efbe0a05c505479f9861125:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/php-pecl-yac
 * [new ref]         69768b522eb04f709efbe0a05c505479f9861125 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 69768b5 modernize the spec file