$ git clone -n https://src.fedoraproject.org/rpms/rust-h3-quinn.git /var/lib/mock/f45-build-42250-791/root/chroot_tmpdir/scmroot/rust-h3-quinn
Cloning into '/var/lib/mock/f45-build-42250-791/root/chroot_tmpdir/scmroot/rust-h3-quinn'...
$ git fetch origin e7874a004d136c6508e480d96f87b8828acf48c2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-h3-quinn
 * [new ref]         e7874a004d136c6508e480d96f87b8828acf48c2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e7874a0 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild