Closed
Description
Bug report
Bug summary
When importing matplotlib.pyplot, the interpreter hangs indefinitely. This only seems to happen in an environment where $HOME/.matplotlib does not yet exist. I reproduced this in my environment by renaming the existing$HOME/.matplotlib directory. Critically, this only seems to occur when running the script from $HOME.
A valid workaround seems to be to move to any other directory and run the same command. After this, a new .matplotlib/ directory now exists in $HOME, and the previous command works fine when running from $HOME.
In order to reproduce this I created a conda environment with the following command:
$ conda create -n mpl-test python ipython matplotlib
Everything came from the default channel.
Code for reproduction
from matplotlib import pytplot as pltActual outcome
This hangs indefinitely. When I hit CTRL-C, I get something like the following:
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/pyplot.py in <module>
30 from cycler import cycler
31 import matplotlib
---> 32 import matplotlib.colorbar
33 import matplotlib.image
34 from matplotlib import rcsetup, style
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/colorbar.py in <module>
30 import matplotlib.collections as collections
31 import matplotlib.colors as colors
---> 32 import matplotlib.contour as contour
33 import matplotlib.cm as cm
34 import matplotlib.gridspec as gridspec
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/contour.py in <module>
16 import matplotlib.colors as mcolors
17 import matplotlib.collections as mcoll
---> 18 import matplotlib.font_manager as font_manager
19 import matplotlib.text as text
20 import matplotlib.cbook as cbook
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in <module>
1361 raise
1362 except Exception:
-> 1363 _rebuild()
1364 else:
1365 _rebuild()
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in _rebuild()
1342 global fontManager
1343
-> 1344 fontManager = FontManager()
1345
1346 if _fmcache:
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in __init__(self, size, weight)
976 self.defaultFont = {}
977
--> 978 ttffiles = findSystemFonts(paths) + findSystemFonts()
979 self.defaultFont['ttf'] = next(
980 (fname for fname in ttffiles
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in findSystemFonts(fontpaths, fontext)
268 # check for OS X & load its fonts if present
269 if sys.platform == 'darwin':
--> 270 fontfiles.update(OSXInstalledFonts(fontext=fontext))
271
272 elif isinstance(fontpaths, str):
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in OSXInstalledFonts(directories, fontext)
216 directories = OSXFontDirectories
217 return [path
--> 218 for directory in directories
219 for ext in get_fontext_synonyms(fontext)
220 for path in list_fonts(directory, ext)]
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in <listcomp>(.0)
218 for directory in directories
219 for ext in get_fontext_synonyms(fontext)
--> 220 for path in list_fonts(directory, ext)]
221
222
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in list_fonts(directory, extensions)
155 extensions = ["." + ext for ext in extensions]
156 return [str(path)
--> 157 for path in filter(Path.is_file, Path(directory).glob("**/*.*"))
158 if path.suffix in extensions]
159
~/miniconda3/envs/mpl-test/lib/python3.7/site-packages/matplotlib/font_manager.py in <listcomp>(.0)
154 """
155 extensions = ["." + ext for ext in extensions]
--> 156 return [str(path)
157 for path in filter(Path.is_file, Path(directory).glob("**/*.*"))
158 if path.suffix in extensions]
~/miniconda3/envs/mpl-test/lib/python3.7/pathlib.py in glob(self, pattern)
1080 raise NotImplementedError("Non-relative patterns are unsupported")
1081 selector = _make_selector(tuple(pattern_parts))
-> 1082 for p in selector.select_from(self):
1083 yield p
1084
~/miniconda3/envs/mpl-test/lib/python3.7/pathlib.py in _select_from(self, parent_path, is_dir, exists, scandir)
543 for starting_point in self._iterate_directories(parent_path, is_dir, scandir):
544 for p in successor_select(starting_point, is_dir, exists, scandir):
--> 545 if p not in yielded:
546 yield p
547 yielded.add(p)
~/miniconda3/envs/mpl-test/lib/python3.7/pathlib.py in __hash__(self)
724 return self._hash
725 except AttributeError:
--> 726 self._hash = hash(tuple(self._cparts))
727 return self._hash
728
~/miniconda3/envs/mpl-test/lib/python3.7/pathlib.py in _cparts(self)
710 # Cached casefolded parts, for hashing and comparison
711 try:
--> 712 return self._cached_cparts
713 except AttributeError:
714 self._cached_cparts = self._flavour.casefold_parts(self._parts)
KeyboardInterrupt:
Expected outcome
It shouldn't hang! 😝
Matplotlib version
- Operating system: OSX 10.12.6 (High Sierra)
- Matplotlib version: 3.0.0
- Matplotlib backend (
print(matplotlib.get_backend())): This command hangs also, but after performing the workaround I get'TkAgg' - Python version: 3.7.0, but we initially saw this on 3.6.6.
- Jupyter version (if applicable): N/A
- Other libraries: The only other thing installed in this environment is IPython
cc @brechmos-stsci who initially encountered this issue and discovered the workaround.