$ git clone -n https://src.fedoraproject.org/rpms/rust-flate2.git /var/lib/mock/f39-build-1523097-35985/root/chroot_tmpdir/scmroot/rust-flate2
Cloning into '/var/lib/mock/f39-build-1523097-35985/root/chroot_tmpdir/scmroot/rust-flate2'...
$ git fetch origin 49dc614168e15ae01ff696feff748f27adedbce4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-flate2
 * [new ref]         49dc614168e15ae01ff696feff748f27adedbce4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 49dc614 Update to version 1.0.28; Fixes RHBZ#2243817