cannot install scikit-allel[full] due to its broken dependency (bcolz) with recent toolchains

[grahamgower]

Do we actually need the full option to scikit-allel? It depends on bcolz, which is unmaintained and fails to build on my system:

    c-blosc/blosc/shuffle.c:170:1: error: conflicting types for ‘_xgetbv’
      170 | _xgetbv(uint32_t xcr) {
          | ^~~~~~~
    In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/include/immintrin.h:43,
                     from c-blosc/blosc/blosc-common.h:77,
                     from c-blosc/blosc/shuffle.h:18,
                     from c-blosc/blosc/shuffle.c:10:
    /usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/include/xsaveintrin.h:60:1: note: previous definition of ‘_xgetbv’ was here
       60 | _xgetbv (unsigned int __A)
          | ^~~~~~~
    In file included from c-blosc/blosc/shuffle.c:11:
    c-blosc/blosc/shuffle-generic.h:61:13: warning: ‘unshuffle_generic_inline’ defined but not used [-Wunused-function]
       61 | static void unshuffle_generic_inline(const size_t type_size,
          |             ^~~~~~~~~~~~~~~~~~~~~~~~
    c-blosc/blosc/shuffle-generic.h:32:13: warning: ‘shuffle_generic_inline’ defined but not used [-Wunused-function]
       32 | static void shuffle_generic_inline(const size_t type_size,
          |             ^~~~~~~~~~~~~~~~~~~~~~
    error: command 'gcc' failed with exit status 1
    ----------------------------------------
ERROR: Command errored out with exit status 1: /usr/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-bu1ymyss/bcolz/setup.py'"'"'; __file__='"'"'/tmp/pip-install-bu1ymyss/bcolz/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-w7s1k7os/install-record.txt --single-version-externally-managed --user --prefix= --compile --install-headers /home/grg/.local/include/python3.8/bcolz Check the logs for full command output.

[grahamgower]

Blosc/bcolz#409

[jeromekelleher]

I doubt we need it.