FIX (partial): sphinx_gallery_conf not pickleable

Author: NirobNabil

doc/conf.py

@@ -228,22 +228,6 @@ def _check_dependencies():
 }
 
 
-# Sphinx gallery configuration
-
-def matplotlib_reduced_latex_scraper(block, block_vars, gallery_conf,
-                                     **kwargs):
-    """
-    Reduce srcset when creating a PDF.
-
-    Because sphinx-gallery runs *very* early, we cannot modify this even in the
-    earliest builder-inited signal. Thus we do it at scraping time.
-    """
-    from sphinx_gallery.scrapers import matplotlib_scraper
-
-    if gallery_conf['builder_name'] == 'latex':
-        gallery_conf['image_srcset'] = []
-    return matplotlib_scraper(block, block_vars, gallery_conf, **kwargs)
-
 gallery_dirs = [f'{ed}' for ed in
                 ['gallery', 'tutorials', 'plot_types', 'users/explain']
                 if f'{ed}/*' not in skip_subdirs]
@@ -261,7 +245,7 @@ def matplotlib_reduced_latex_scraper(block, block_vars, gallery_conf,
     'examples_dirs': example_dirs,
     'filename_pattern': '^((?!sgskip).)*$',
     'gallery_dirs': gallery_dirs,
-    'image_scrapers': (matplotlib_reduced_latex_scraper, ),
+    'image_scrapers': ("sphinxext.util.matplotlib_reduced_latex_scraper", ),
     'image_srcset': ["2x"],
     'junit': '../test-results/sphinx-gallery/junit.xml' if CIRCLECI else '',
     'matplotlib_animations': True,
@@ -272,11 +256,11 @@ def matplotlib_reduced_latex_scraper(block, block_vars, gallery_conf,
     'reset_modules': (
         'matplotlib',
         # clear basic_units module to re-register with unit registry on import
-        lambda gallery_conf, fname: sys.modules.pop('basic_units', None)
+        "sphinxext.util.clear_basic_unit"
     ),
-    'subsection_order': gallery_order.sectionorder,
+    'subsection_order': "sphinxext.gallery_order.sectionorder",
     'thumbnail_size': (320, 224),
-    'within_subsection_order': gallery_order.subsectionorder,
+    'within_subsection_order': "sphinxext.gallery_order.subsectionorder",
     'capture_repr': (),
     'copyfile_regex': r'.*\.rst',
 }

doc/sphinxext/gallery_order.py

@@ -105,7 +105,7 @@ def __call__(self, item):
 explicit_subsection_order = [item + ".py" for item in list_all]
 
 
-class MplExplicitSubOrder:
+class MplExplicitSubOrder(ExplicitOrder):
     """For use within the 'within_subsection_order' key."""
     def __init__(self, src_dir):
         self.src_dir = src_dir  # src_dir is unused here
@@ -119,6 +119,9 @@ def __call__(self, item):
             # ensure not explicitly listed items come last.
             return "zzz" + item
 
+# from sphinx.confing import is_serializable
+# assert is_serializable(MplExplicitSubOrder)
+
 
 # Provide the above classes for use in conf.py
 sectionorder = MplExplicitOrder(explicit_order_folders)

doc/sphinxext/util.py

@@ -0,0 +1,20 @@
+import sys
+
+# Sphinx gallery configuration
+def matplotlib_reduced_latex_scraper(block, block_vars, gallery_conf,
+                                     **kwargs):
+    """
+    Reduce srcset when creating a PDF.
+
+    Because sphinx-gallery runs *very* early, we cannot modify this even in the
+    earliest builder-inited signal. Thus we do it at scraping time.
+    """
+    from sphinx_gallery.scrapers import matplotlib_scraper
+
+    if gallery_conf['builder_name'] == 'latex':
+        gallery_conf['image_srcset'] = []
+    return matplotlib_scraper(block, block_vars, gallery_conf, **kwargs)
+
+
+def clear_basic_unit(gallery_conf, fname):
+    return sys.modules.pop('basic_units', None)