$ git clone -n https://src.fedoraproject.org/rpms/rust-system-deps.git /var/lib/mock/f39-build-1623072-38896/root/chroot_tmpdir/scmroot/rust-system-deps
Cloning into '/var/lib/mock/f39-build-1623072-38896/root/chroot_tmpdir/scmroot/rust-system-deps'...
$ git fetch origin f861278ce8af8c98ec8de67dcee2c5943816c07b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-system-deps
 * [new ref]         f861278ce8af8c98ec8de67dcee2c5943816c07b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f861278 Update to version 6.1.2; Fixes RHBZ#2241939