Stemming algorithm 'porter' not found with snowballstemmer 3.0.0 #13533
Description
Sphinx failures with snowballstemmer 3
UPDATE: snowballstemmer 3 has been yanked, pinning is now unneeded.
snowballstemmer==3.0.0 causes Sphinx builds to fail. We've asked upstream about this. For now, the best quick fix will be to pin to snowballstemmer<3, either directly or via a constraints file (pip, uv).
xref:
Describe the bug
snowballstemmer 3.0.0 has been released about an hour ago and it seems to break Sphinx. This is the contents of the sphinx-err-*.log file:
Versions
========
* Platform: win32; (Windows-11-10.0.22631-SP0)
* Python version: 3.12.9 (CPython)
* Sphinx version: 8.2.3
* Docutils version: 0.21.2
* Jinja2 version: 3.1.6
* Pygments version: 2.19.1
Last Messages
=============
looking for now-outdated files...
none found
pickling environment...
done
checking consistency...
done
preparing documents...
failed
Loaded Extensions
=================
* sphinx.ext.mathjax (8.2.3)
* alabaster (1.0.0)
* sphinxcontrib.applehelp (2.0.0)
* sphinxcontrib.devhelp (2.0.0)
* sphinxcontrib.htmlhelp (2.1.0)
* sphinxcontrib.serializinghtml (2.0.0)
* sphinxcontrib.qthelp (2.0.0)
Traceback
=========
Traceback (most recent call last):
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\cmd\build.py", line 432, in build_main
app.build(args.force_all, args.filenames)
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\application.py", line 426, in build
self.builder.build_update()
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\builders\__init__.py", line 375, in build_update
self.build(
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\builders\__init__.py", line 454, in build
self.write(docnames, updated_docnames, method)
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\builders\__init__.py", line 729, in write
self.prepare_writing(docnames)
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\builders\html\__init__.py", line 438, in prepare_writing
self.indexer = IndexBuilder(
^^^^^^^^^^^^^
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\search\__init__.py", line 317, in __init__
self.lang = lang_class(options)
^^^^^^^^^^^^^^^^^^^
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\search\__init__.py", line 95, in __init__
self.init(options)
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\sphinx\search\en.py", line 215, in init
self.stemmer = snowballstemmer.stemmer('porter')
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\home\tmp\sphinx-bug\.venv\Lib\site-packages\snowballstemmer\__init__.py", line 27, in stemmer
raise KeyError("Stemming algorithm '%s' not found" % lang)
KeyError: "Stemming algorithm 'porter' not found"Additional context
-
Output of
pip listin the virtual environment:Package Version ----------------------------- --------- snowballstemmer 3.0.0 Sphinx 8.2.3 -
Running
pip install snowballstemmer==2.2.0fixes the issue.