Comment 6 for bug 2016003

This looks like a type issue that happens because Python 3 is stricter than Python 2 was:

> /home/jelmer/src/breezy/brz-3.3.2/breezy/bzr/index.py(670)_find_index()
-> result = bisect_right(range_map, key) - 1
(Pdb) p range_map
[((), (b'Arch-1:csardi@guzu%igraph--main--0.4--patch-164',)), ((b'Arch-1:csardi@guzu%igraph--main--0.4--patch-63',), (b'Arch-1:<email address hidden>%igraph--main--0.2--patch-109',)), ((b'Arch-1:<email address hidden>%igraph--main--0.2--patch-130',), (b'Arch-1:<email address hidden>%igraph--main--0.2--patch-165',)), ((b'Arch-1:<email address hidden>%igraph--main--0.2--patch-212',), (b'Arch-1:<email address hidden>%igraph--main--0.2--patch-37',)), ((b'Arch-1:<email address hidden>%igraph--main--0.4--patch-172',), (b'Arch-1:<email address hidden>%igraph--main--0.4--patch-207',)), ((b'Arch-1:<email address hidden>%igraph--main--0.6--patch-125',), (b'Arch-1:<email address hidden>%igraph--main--0.6--patch-160',)), ((b'Arch-1:<email address hidden>%igraph--main--0.6--patch-60',), (b'Arch-1:<email address hidden>%igraph--main--0.6--patch-96',)), ((b'Arch-1:csardi@shanna%igraph--main--0.2--patch-3',), (b'Arch-1:csardi@szaffi%igraph--main--0.2--patch-130',)), ((b'Arch-1:csardi@szaffi%igraph--main--0.2--patch-147',), (b'Arch-1:csardi@szaffi%igraph--main--0.2--patch-227',)), ((b'Arch-1:csardi@szaffi2%igraph--main--0.5--patch-257',), (b'Arch-1:csardi@szaffi2%igraph--main--0.5--patch-81',)), ((b'csardi@csardi-desktop-20100617141041-nndb4vxuix76wmbk',), (b'csardi@strider-20100618143323-ry24wclpgs1wcffy',))]
(Pdb) p key
((b'Arch-1:csardi@shanna%igraph--main--0.2--patch-3',), b'')

It looks like the () is inserted for the header of the index, but it's not clear to me why this works in other situations.