René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"test_backend_qt tests failing","articleBody":"Seems to be present in all recent builds, here's a sample error from pytest:\r\n\r\n```python\r\nlib/matplotlib/tests/test_backends_interactive.py:117: Failed\r\n----------------------------- Captured stderr call -----------------------------\r\nFailed to connect to Mir: Failed to connect to server socket: No such file or directory\r\nUnable to init server: Could not connect: Connection refused\r\nFailed to connect to Mir: Failed to connect to server socket: No such file or directory\r\nUnable to init server: Could not connect: Connection refused\r\n(-c:14609): Gdk-CRITICAL **: gdk_cursor_new_for_display: assertion 'GDK_IS_DISPLAY (display)' failed\r\nTraceback (most recent call last):\r\n  File \"/home/travis/build/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtk3.py\", line 43, in \u003cmodule\u003e\r\n    cursors.MOVE          : Gdk.Cursor.new(Gdk.CursorType.FLEUR),\r\nTypeError: constructor returned NULL\r\nDuring handling of the above exception, another exception occurred:\r\nTraceback (most recent call last):\r\n  File \"\u003cstring\u003e\", line 7, in \u003cmodule\u003e\r\n  File \"/home/travis/build/matplotlib/matplotlib/lib/matplotlib/pyplot.py\", line 2341, in \u003cmodule\u003e\r\n    switch_backend(rcParams[\"backend\"])\r\n  File \"/home/travis/build/matplotlib/matplotlib/lib/matplotlib/pyplot.py\", line 207, in switch_backend\r\n    backend_mod = importlib.import_module(backend_name)\r\n  File \"/home/travis/virtualenv/python3.6.7/lib/python3.6/importlib/__init__.py\", line 126, in import_module\r\n    return _bootstrap._gcd_import(name[level:], package, level)\r\n  File \"/home/travis/build/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtk3agg.py\", line 4, in \u003cmodule\u003e\r\n    from . import backend_agg, backend_cairo, backend_gtk3\r\n  File \"/home/travis/build/matplotlib/matplotlib/lib/matplotlib/backends/backend_gtk3.py\", line 52, in \u003cmodule\u003e\r\n    raise ImportError(exc)\r\nImportError: constructor returned NULL\r\n```","author":{"url":"https://github.com/dstansby","@type":"Person","name":"dstansby"},"datePublished":"2019-01-16T21:08:20.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/13201/matplotlib/issues/13201"}