$ git clone -n https://src.fedoraproject.org/rpms/rust-arrow-string.git /var/lib/mock/f45-build-40200-769/root/chroot_tmpdir/scmroot/rust-arrow-string
Cloning into '/var/lib/mock/f45-build-40200-769/root/chroot_tmpdir/scmroot/rust-arrow-string'...
$ git fetch origin 6ad1a40c44a55e11f3f95d99fe06799c62a17eae:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-arrow-string
 * [new ref]         6ad1a40c44a55e11f3f95d99fe06799c62a17eae -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6ad1a40 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild