Transifex does not like the new bridgedb.pot file

The new bridgedb.pot file has been generated in a different way than previous files. Transifex imports the file, but wrongly displays 100% translated for each language.

I first thought this was an issue with Transifex and reported the issue on github. Jason, one of our support assistants, later emailed me a link to an FAQ suggesting there could be something wrong with the .pot file.

The new file is not much different from an older version, but contains a "Generated-By: Babel 0.9.6\n"-header and lines such as "#, python-format".

How was this file generated? does BridgeDB want files as .po or in some other format?