$ git clone -n https://src.fedoraproject.org/rpms/rust-quinn.git /var/lib/mock/f45-build-44188-811/root/chroot_tmpdir/scmroot/rust-quinn
Cloning into '/var/lib/mock/f45-build-44188-811/root/chroot_tmpdir/scmroot/rust-quinn'...
$ git fetch origin fbb080513973e7bb150a754c61d24e05a89126c6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-quinn
 * [new ref]         fbb080513973e7bb150a754c61d24e05a89126c6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fbb0805 Update to version 0.11.12; Fixes RHBZ#2533015