$ git clone -n https://src.fedoraproject.org/rpms/rust-schemars.git /var/lib/mock/f42-build-side-1-3584337-46893/root/chroot_tmpdir/scmroot/rust-schemars
Cloning into '/var/lib/mock/f42-build-side-1-3584337-46893/root/chroot_tmpdir/scmroot/rust-schemars'...
$ git fetch origin 02b68d9071329365f22a55fb69c1c3f93f11a935:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-schemars
 * [new ref]         02b68d9071329365f22a55fb69c1c3f93f11a935 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 02b68d9 Update to version 1.0.3; Fixes RHBZ#2368633