Description:

1. python-blosc 1.10.6-3 is missing the compiled python bytecode due to a bug[0] in python-scikit-build.
2. python-blosc is compiled with cmake build type `Release` which adds `-O3 -DNDEBUG` arguments to compiler
commands and this overrides the default -O2 flag. The commands can be inspected by appending
`-DCMAKE_VERBOSE_MAKEFILE=ON` option to `setup.py build`.

Solution:

1. Either wait for scikit-build upstream to release a fixed version or backport the fix[0], and rebuild the package.
2. Replace all `setup.py` commands in `build()` with
```
python setup.py build --build-type None -DCMAKE_C_FLAGS_INIT=-DNDEBUG
```
This specifies the None build type as recommended in CMake package guidelines. Adding `-DNDEBUG` option
is necessary to avoid `__FILE__` macros as these would leave references to $srcdir. Also the
`setup.py install` command in `package()` needs to be changed to
```
python setup.py --skip-cmake install --skip-build --root="$pkgdir" --optimize=1
```
The `--skip-cmake` option prevents rebuilding in `install`, otherwise the build type and other build flags
need to be specified again. See scikit-build documentation[1] for more details.

Also two other minor things can be improved in the PKGBUILD:
1. Upstream provides a way to compile with system blosc by using `-DUSE_SYSTEM_BLOSC=ON`,
there is no need to patch the sources in `prepare()`.
2. Build-time dependency on `ninja` can be dropped by giving `-G "Unix Makefiles"` option[1]
to `setup.py build`. CMake uses then standard Makefiles instead of ninja.

The patch provided as an attachment fixes these issues except the missing bytecode.

Additional info:
* package version(s)
* python-blosc 1.10.6-3
* python-scikit-build 0.13.1-1
* link to upstream bug report, if any
* [0] https://github.com/scikit-build/scikit-build/pull/678
* [1] https://scikit-build.readthedocs.io/en/latest/usage.html#command-line-options