The arguments of EpubBuilder.build_container() is deprecated.

CHANGES

@@ -58,7 +58,8 @@ Deprecated
 
 * Support for evaluating Python 2 syntax is deprecated. This includes
   configuration files which should be converted to Python 3.
-* The arguments of ``EpubBuilder.build_mimetype()``
+* The arguments of ``EpubBuilder.build_mimetype()``,
+  ``EpubBuilder.build_container()``
 * The ``encoding`` argument of ``autodoc.Documenter.get_doc()``,
   ``autodoc.DocstringSignatureMixin.get_doc()``,
   ``autodoc.DocstringSignatureMixin._find_signature()``, and

doc/extdev/index.rst

@@ -242,7 +242,8 @@ The following is a list of deprecated interfaces.
      - 4.0
      - N/A
 
-   * - arguments of ``EpubBuilder.build_mimetype()``
+   * - arguments of ``EpubBuilder.build_mimetype()``,
+       ``EpubBuilder.build_container()``.
      - 2.0
      - 4.0
      - N/A

sphinx/builders/_epub_base.py

@@ -485,9 +485,15 @@ class EpubBuilder(StandaloneHTMLBuilder):
         copy_asset_file(path.join(self.template_dir, 'mimetype'),
                         path.join(outdir, outname))
 
-    def build_container(self, outdir, outname):
+    def build_container(self, outdir=None, outname='META-INF/container.xml'):
         # type: (str, str) -> None
         """Write the metainfo file META-INF/container.xml."""
+        if outdir:
+            warnings.warn('The arguments of EpubBuilder.build_container() is deprecated.',
+                          RemovedInSphinx40Warning, stacklevel=2)
+        else:
+            outdir = self.outdir
+
         logger.info(__('writing %s file...'), outname)
         filename = path.join(outdir, outname)
         ensuredir(path.dirname(filename))

sphinx/builders/epub3.py

@@ -79,7 +79,7 @@ class Epub3Builder(_epub_base.EpubBuilder):
         self.validate_config_value()
         self.get_toc()
         self.build_mimetype()
-        self.build_container(self.outdir, 'META-INF/container.xml')
+        self.build_container()
         self.build_content(self.outdir, 'content.opf')
         self.build_navigation_doc(self.outdir, 'nav.xhtml')
         self.build_toc(self.outdir, 'toc.ncx')