pure: use string for exception in the pure version of base85 Without this change, running the test with python3 and --pure gives the following error:: --- /home/marmoute/src/mercurial-dev/tests/test-import-git.t +++ /home/marmoute/src/mercurial-dev/tests/test-import-git.t.err @@ -518,7 +518,7 @@ > > EOF applying patch from stdin - abort: could not decode "binary2" binary patch: bad base85 character at position 6 + abort: could not decode "binary2" binary patch: b'bad base85 character at position 6' [255] $ hg revert -aq To make the cext implementation, we use a "native" string for the exception. This fix the test failure.