[matplotlib-devel] tk backend broken (somehow?)

[Benjamin R. <ben...@ou...>]

And with my continuing saga of backend-specific things...

I was using conda, but because it does not ship with pygtk support, I had
to manually install pygtk into the conda environment and then install
matplotlib from source. All that seemed to work fine when I worked on Wx
and Gtk examples for my book.

I went back to a (previously working) Tk example to polish it, and I get
all sorts of errors now. I have tried multiple releases of matplotlib from
source (doing a git clean -fxd between them), all with similar errors. In
fact, with master, the error causes a segfault:

ben@tigger:~/Documents/InteractiveMPL$ python chp5/slider_tk.py
Exception in Tkinter callback
Traceback (most recent call last):
  File "/home/ben/miniconda/lib/python2.7/lib-tk/Tkinter.py", line 1486, in
__call__
    return self.func(*args)
  File
"/home/ben/miniconda/lib/python2.7/site-packages/matplotlib-1.5.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_tkagg.py",
line 278, in resize
    self.show()
  File
"/home/ben/miniconda/lib/python2.7/site-packages/matplotlib-1.5.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_tkagg.py",
line 350, in draw
    tkagg.blit(self._tkphoto, self.renderer._renderer, colormode=2)
  File
"/home/ben/miniconda/lib/python2.7/site-packages/matplotlib-1.5.x-py2.7-linux-x86_64.egg/matplotlib/backends/tkagg.py",
line 30, in blit
    id(data), colormode, id(bbox_array))
TclError
alloc: invalid block: 0x2cfe3b0: 0 0
Aborted (core dumped)

The line in question is (at least in v1.3.1, it is slightly different in
more recent versions):
tk.call("PyAggImagePhoto", photoimage, id(aggimage), colormode,
id(bbox_array))

This happens regardless of what example I use (my own or otherwise). There
is no blit-specific code in the examples. All of this worked with the
conda-supplied matplotlib, but never the
from-source-into-a-conda-environment install.

Thoughts?
Ben Root