Package: dpkg-dev More and more packages are adding unicode files as unicode support has become more reliable and available. The package building process is not guaranteed to happen in a unicode locale since the Debian default locale is LC_ALL=C, which is ASCII not UTF-8. Reading UTF-8 filenames when the system is using ASCII causes errors (Python makes them very visible, for example).
mbiebl, youpi, wRAR, bunk, and I had a discussion in #debian-devel. It looks like setting the default locale to C.UTF-8 in dpkg-buildpackage is an easy way to improve this situation a lot. Any package that needs an encoding besides UTF-8 could always set it by adding something like this to debian/rules: export LC_ALL = C Setting C.UTF-8 as the global default in Debian would be the best solution to this and many other issues, but that's a much much larger project: https://sourceware.org/glibc/wiki/Proposals/C.UTF-8