pathutil: use util.pathto() to calculate relative cwd in canonpath() os.path.relpath() exploded if the 'root' and 'cwd' directories had different drive letters. I noticed this in TortoiseHg when typing a fileset into the filter, and it kept complaining until the closing '()' was typed. This was reproducible on the command line with: $ cd /d $ hg -R /c/Users/Matt/Projects/hg files 'set:e' Traceback (most recent call last): ... File "mercurial\pathutil.pyc", line 182, in canonpath File "ntpath.pyc", line 529, in relpath ValueError: path is on drive c:, start on drive d: