$ git clone -n https://src.fedoraproject.org/rpms/rust-darling0.14.git /var/lib/mock/f41-build-side-1-3124861-39482/root/chroot_tmpdir/scmroot/rust-darling0.14
Cloning into '/var/lib/mock/f41-build-side-1-3124861-39482/root/chroot_tmpdir/scmroot/rust-darling0.14'...
$ git fetch origin f034a907e005090650b409d8d360e30a1a21e431:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-darling0.14
 * [new ref]         f034a907e005090650b409d8d360e30a1a21e431 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f034a90 compat package no longer needed