# Version 4.5.21

Version 4.5.21 of mod_wsgi can be obtained from:

> https://codeload.github.com/GrahamDumpleton/mod_wsgi/tar.gz/4.5.21

## Bugs Fixed

- Installation using `pip` or `setup.py` install was failing on MacOS X High Sierra with latest Xcode as Apple doesn’t even include the `apxs` program at all.

  Note you still cannot use the configure/make/make install method of deploying mod_wsgi to MacOS X. You need to use the `pip install` method.

- Speculated that crashes on daemon process shutdown were being caused by a race condition around accessing Python C API when interpreter was being destroyed. There was a check in place to avoid this but may not have been robust enough depending on how memory cache worked for threads running across multi core machine. Now use a dedicated thread mutex to avoid race condition between main process thread and Python interpreter deadlock detection thread.

## Features Changed

- Set `wsgi.input_terminated` to `True` in WSGI environment. This is a unofficial extension to WSGI specification proposed by Armin Ronacher for a WSGI server/middleware to flag that it is safe to read to the end of input and that `CONTENT_LENGTH` can be ignored. This is to be able to support chunked request content, but also anything which mutates the request content length but which can’t easily change the `CONTENT_LENGTH`, such as occurs when request content is compressed and is decompressed by the Apache web server.

  The ability to safely read until end of input was always present in mod_wsgi, but there was no way in the WSGI specification for a WSGI server to tell a WSGI application this was the case. Prior attempts to include something to deal with this in the WSGI specification when it was updated in PEP 3333 were ignored. This is why now an unofficial way of doing it is being adopted by WSGI servers separate to the WSGI specification.