$ git clone -n https://src.fedoraproject.org/rpms/rust-backtrace.git /var/lib/mock/f39-build-1882453-42766/root/chroot_tmpdir/scmroot/rust-backtrace
Cloning into '/var/lib/mock/f39-build-1882453-42766/root/chroot_tmpdir/scmroot/rust-backtrace'...
$ git fetch origin db626ecfe05d2663f84007741b6de9554ec3d3ac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-backtrace
 * [new ref]         db626ecfe05d2663f84007741b6de9554ec3d3ac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at db626ec Update to version 0.3.69; Fixes RHBZ#2218705