$ git clone -n https://src.fedoraproject.org/rpms/rust-cursive_core.git /var/lib/mock/f42-build-side-1-3586016-46913/root/chroot_tmpdir/scmroot/rust-cursive_core
Cloning into '/var/lib/mock/f42-build-side-1-3586016-46913/root/chroot_tmpdir/scmroot/rust-cursive_core'...
$ git fetch origin bfb3b5410949f3298c31de9b0ff2eaab11f4107f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cursive_core
 * [new ref]         bfb3b5410949f3298c31de9b0ff2eaab11f4107f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bfb3b54 Update to 0.4.6 (rhbz#2302544)