yasm was apparently broken on i686 on the 'python-build-system' branch,
which was then subsequently merged into master. As a result, many
important package are dependency-failures on i686, including all
gstreamer plugins, and thus all media players and web browsers.
This branch should not have been merged until these issues were fixed.
Now, i686 users won't be able to get important security updates such as
the recent icecat fixes (for which there are active exploits seen in the
wild) in a timely fashion.