$ git clone -n https://src.fedoraproject.org/rpms/rust-tryfn0.2.git /var/lib/mock/f45-build-45770-827/root/chroot_tmpdir/scmroot/rust-tryfn0.2
Cloning into '/var/lib/mock/f45-build-45770-827/root/chroot_tmpdir/scmroot/rust-tryfn0.2'...
$ git fetch origin 261c7dfb7d1159ff5de86070c81a6c02acf4135d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tryfn0.2
 * [new ref]         261c7dfb7d1159ff5de86070c81a6c02acf4135d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 261c7df Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild