$ git clone -n https://src.fedoraproject.org/rpms/rust-gethostname.git /var/lib/mock/f45-build-41892-786/root/chroot_tmpdir/scmroot/rust-gethostname
Cloning into '/var/lib/mock/f45-build-41892-786/root/chroot_tmpdir/scmroot/rust-gethostname'...
$ git fetch origin acc91dd5e0867044dc20d5d363e1a8138aeca5be:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gethostname
 * [new ref]         acc91dd5e0867044dc20d5d363e1a8138aeca5be -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at acc91dd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild