delta-find: use "-1" as depth snapshot-dept for non snapshot in debug
This will help do distinct full snapshot (level 0) and normal delta (not a snapshot, no snapshot level)
#require black test-repo
Black needs the real USERPROFILE in order to run on Windows
#if msys
$ USERPROFILE="$REALUSERPROFILE"
$ export USERPROFILE
#endif
$ cd $RUNTESTDIR/..
$ black --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/**'`