For people encountering this, you need to check two things to resolve the issue.
1) Your locale must be set correctly. If the bzr crash report says your fsenc is 'ANSI_X3.4-1968' rather than 'UTF-8' double check the LANG and LC_* variables are set correctly.
2) All the filenames you are trying to add must be in the encoding specified. With a UTF-8 filesystem, à for instance needs to be the byte sequence '\xc3\xa0' rather than '\xe0'.
For people encountering this, you need to check two things to resolve the issue.
1) Your locale must be set correctly. If the bzr crash report says your fsenc is 'ANSI_X3.4-1968' rather than 'UTF-8' double check the LANG and LC_* variables are set correctly.
2) All the filenames you are trying to add must be in the encoding specified. With a UTF-8 filesystem, à for instance needs to be the byte sequence '\xc3\xa0' rather than '\xe0'.