The pythonX.Y packages stopped building the _fpectl extension. Upstream stopped building this extension a long time ago, however I failed to disable it after a last release ... It's now disabled, and causing some build failures because third party extensions still reference it. The most prominent is python{,3}-numpy which I just NMUed to rebuild against the current pythonX.Y packages (already having a break on the current python{,3}-numpy). If breaks for other packages are needed, please file bug reports for the pythonX.Y packages.
Matthias