It is configurable, but it should be going to your home directory by default.

If you can get into an interactive debugger checking the value of _fmcache will tell you where it is actually trying to write.

Check

from matplotlib import get_cachedir 
import os

cachedir = get_cachedir()
print(os.path.join(cachedir, 'fontList.json'))

on both systems.

We probably should be more cautious when writing the cache out. Exact work:

• catch IOError in font_manager.dump_json. There was some change in filesystem type errors between 2 and 3 iirc
• issue an informative warning about a) why the file was not written b) how to configure the cache_dir to not try to cache the font information.

tagged as 2.1.1 as this is a 'fail on import' type bug.

Thanks @tacaswell ! your snippet is very useful for debugging this error!
Turns out it's indeed writing to $HOME/.matplotlib, but I didn't realize until just now that my local box's home dir doesn't sync with the one on the remote host. And it's the latter one that's full already.

Re-opening this although the OP's issue is fixed, we should not be failing to import in cases like this

@galactica147 thanks for taking the time to report this and glad it is working again.

Hi Team,

I am seeing this issue again.

import seaborn as sn
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/seaborn/init.py", line 2, in
from .rcmod import * # noqa: F401,F403
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/seaborn/rcmod.py", line 7, in
from . import palettes
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/seaborn/palettes.py", line 9, in
from .utils import desaturate, get_color_cycle
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/seaborn/utils.py", line 14, in
import matplotlib.pyplot as plt
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/pyplot.py", line 49, in
import matplotlib.colorbar
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/colorbar.py", line 21, in
from matplotlib import _api, collections, cm, colors, contour, ticker
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/contour.py", line 13, in
from matplotlib.backend_bases import MouseButton
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/backend_bases.py", line 46, in
from matplotlib import (
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/textpath.py", line 8, in
from matplotlib import _text_helpers, dviread, font_manager
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/font_manager.py", line 1447, in
fontManager = _load_fontmanager()
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/font_manager.py", line 1442, in _load_fontmanager
json_dump(fm, fm_path)
File "/opt/test-result-jenie/venv_trj/lib/python3.8/site-packages/matplotlib/font_manager.py", line 1007, in json_dump
_log.warning('Could not save font_manager cache {}'.format(e))
OSError: [Errno 122] Disk quota exceeded

matplotlib version: 3.5.2
seaborn version: 0.11.2

Can't clear the cache as don't have the permissions to do so.
Appreciate any help on the issue, Thanks in Advance.

@av9ash Can you please make a new issue with this information?

Ok will do, thanks.