The arguments of EpubBuilder.build_epub() is deprecated.

CHANGES

@@ -60,7 +60,7 @@ Deprecated
   configuration files which should be converted to Python 3.
 * The arguments of ``EpubBuilder.build_mimetype()``,
   ``EpubBuilder.build_container()``, ``EpubBuilder.bulid_content()``,
-  ``EpubBuilder.build_toc()``
+  ``EpubBuilder.build_toc()`` and ``EpubBuilder.build_epub()``
 * The ``encoding`` argument of ``autodoc.Documenter.get_doc()``,
   ``autodoc.DocstringSignatureMixin.get_doc()``,
   ``autodoc.DocstringSignatureMixin._find_signature()``, and

doc/extdev/index.rst

@@ -244,7 +244,7 @@ The following is a list of deprecated interfaces.
 
    * - arguments of ``EpubBuilder.build_mimetype()``,
        ``EpubBuilder.build_container()``, ``EpubBuilder.build_content()``,
-       ``EpubBuilder.build_toc()``
+       ``EpubBuilder.build_toc()`` and ``EpubBuilder.build_epub()``
      - 2.0
      - 4.0
      - N/A

sphinx/builders/_epub_base.py

@@ -733,13 +733,20 @@ class EpubBuilder(StandaloneHTMLBuilder):
                         path.join(outdir, outname),
                         self.toc_metadata(level, navpoints))
 
-    def build_epub(self, outdir, outname):
+    def build_epub(self, outdir=None, outname=None):
         # type: (str, str) -> None
         """Write the epub file.
 
         It is a zip file with the mimetype file stored uncompressed as the first
         entry.
         """
+        if outdir:
+            warnings.warn('The arguments of EpubBuilder.build_epub() is deprecated.',
+                          RemovedInSphinx40Warning, stacklevel=2)
+        else:
+            outdir = self.outdir
+            outname = self.config.epub_basename + '.epub'
+
         logger.info(__('writing %s file...'), outname)
         epub_filename = path.join(outdir, outname)
         with ZipFile(epub_filename, 'w', ZIP_DEFLATED) as epub:

sphinx/builders/epub3.py

@@ -83,7 +83,7 @@ class Epub3Builder(_epub_base.EpubBuilder):
         self.build_content()
         self.build_navigation_doc(self.outdir, 'nav.xhtml')
         self.build_toc()
-        self.build_epub(self.outdir, self.config.epub_basename + '.epub')
+        self.build_epub()
 
     def validate_config_value(self):
         # type: () -> None