following will not be formatted:
- automagics (e.g. `pip install black`)
-- non-Python cell magics (e.g. `%%writeline`)
+- non-Python cell magics (e.g. `%%writeline`). These can be added with the flag
+ `--python-cell-magics`, e.g. `black --python-cell-magics writeline hello.ipynb`.
- multiline magics, e.g.:
```python
errors is not a goal. It can format all code accepted by CPython (if you find an example
where that doesn't hold, please report a bug!), but it may also format some code that
CPython doesn't accept.
+
+(labels/mypyc-support)=
+
+## What is `compiled: yes/no` all about in the version output?
+
+While _Black_ is indeed a pure Python project, we use [mypyc] to compile _Black_ into a
+C Python extension, usually doubling performance. These compiled wheels are available
+for 64-bit versions of Windows, Linux (via the manylinux standard), and macOS across all
+supported CPython versions.
+
+Platforms including musl-based and/or ARM Linux distributions, and ARM Windows are
+currently **not** supported. These platforms will fall back to the slower pure Python
+wheel available on PyPI.
+
+If you are experiencing exceptionally weird issues or even segfaults, you can try
+passing `--no-binary black` to your pip install invocation. This flag excludes all
+wheels (including the pure Python wheel), so this command will use the [sdist].
+
+[mypyc]: https://mypyc.readthedocs.io/en/latest/
+[sdist]:
+ https://packaging.python.org/en/latest/glossary/#term-Source-Distribution-or-sdist