$ git clone -n https://src.fedoraproject.org/rpms/rubygem-isolate.git /var/lib/mock/f45-build-35036-693/root/chroot_tmpdir/scmroot/rubygem-isolate
Cloning into '/var/lib/mock/f45-build-35036-693/root/chroot_tmpdir/scmroot/rubygem-isolate'...
$ git fetch origin e3e9ec411161a52d26f01197f460c8eabc24cf1f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-isolate
 * [new ref]         e3e9ec411161a52d26f01197f460c8eabc24cf1f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e3e9ec4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild