$ git clone -n https://src.fedoraproject.org/rpms/mingw-libsigc++20.git /var/lib/mock/f45-build-18569-521/root/chroot_tmpdir/scmroot/mingw-libsigc++20
Cloning into '/var/lib/mock/f45-build-18569-521/root/chroot_tmpdir/scmroot/mingw-libsigc++20'...
$ git fetch origin 1f985c63dbfd302d4ca1d55c71f442c2a06bfca4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mingw-libsigc++20
 * [new ref]         1f985c63dbfd302d4ca1d55c71f442c2a06bfca4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1f985c6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild