You can disable the osx backend in setup.cfg by adding:

[gui_support]
macosx = False

it will then fall back to the next available backend.

My understanding is that the macosx backend has never worked on a non-framework Python, so perhaps in the past a different backend was being selected by default?

Events are broken on non-framework builds, but standard plotting works. For instance, anaconda ships with a non-framework build and mpl 1.2.1. Basic plotting works, but don't try to connect to a key_press_event.

I guess this leads to a reasonable question, should we allow mostly-functional installs of matplotlib? There is the real possibility of getting blamed for events not working, even when warn the user that running non-framework python builds will void the warranty. However, some folks (yt for example) may not use those corners of mpl and may be quite happy otherwise.

@mdboom just tried building matplotlib using your suggested modifications to setup.cfg and pylab still fails to import with the same error in the macosx backend. I can't find the place in the matplotlib codebase where the macosx config option is parsed so I'm not sure if this is a bug of if I should be doing something slightly different.

In setupext.py, BackendMacOSX inherits from OptionalBackendPackage. OptionalBackendPackage.get_config() reads the gui_support section from setup.cfg. get_config() ought to return the value in setup.cfg

ah, it was because I had a typo! Thanks for the guidance @mrterry.

@mdboom's workaround seems sufficient for our purposes. I'm going to leave this open so a matplotlib dev can close it if they agree.

Hi guys, @ngoldbaum @mdboom,
Thanks your discussion. This problem puzzled me for a long time~~

Given that there are some deep-level event handling done within mpl, I
would argue that if non-framework build pythons can't process events
correctly, then we are just asking for trouble if we allow non-framework
builds. Furthermore, it is entirely possible that in the future, mpl will
be going with a more event-driven architecture (see the direction of
WebAgg). Therefore, getting users off of non-framework builds will be
important.

Closing this as (my understanding) is that this is a fundamental issue with OSX.

Also see #3367 and links there in.

@efiring