isal incompatible with apple silicon

[poneill]

installing the python isal on an M2 mac yields the following error:

ERROR: Failed building wheel for isal

which afaict is expected because ISA-L doesn't support mac ARM (see e.g. pycompression/python-isal#114 (comment)).

isal is currently used to provide igzip. Possible resolutions include:

1. Reverting to vanilla gzip throughout.
2. Attempting to install igzip if available and falling back to gzip upon failure.
3. Re-architecting search to avoid the need for igzip.
4. Something else?

[akotlar]

Trying to reproduce, and so I can't on my Apple M2 Pro:

(base) alexkotlar@alexkotlars-MacBook-Pro ~ % python --version
Python 3.11.3
(base) alexkotlar@alexkotlars-MacBook-Pro ~ % pip install isal
Requirement already satisfied: isal in ./miniconda3/lib/python3.11/site-packages (1.1.0)
(base) alexkotlar@alexkotlars-MacBook-Pro ~ % 
(base) alexkotlar@alexkotlars-MacBook-Pro ~ % ipython
Python 3.11.3 (main, Apr 19 2023, 18:51:09) [Clang 14.0.6 ]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.12.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from isal import igzip

In [2]: with igzip.open("t.gz", "wb") as f:
   ...:     f.write(bytes("Hello world"))
   ...: 
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[2], line 2
      1 with igzip.open("t.gz", "wb") as f:
----> 2     f.write(bytes("Hello world"))

TypeError: string argument without an encoding

In [3]: with igzip.open("t.gz", "wb") as f:
   ...:     f.write(bytes("Hello world".encode("utf-8")))
   ...: 

In [4]: with igzip.open("t.gz", "rb") as f:
   ...:     print(f.readlines())
   ...: 
[b'Hello world']

This may be because I'm using conda instead of virtualenv.

Looking at ISA-L, the actual library appears to support Apple Silicon as of intel/isa-l#164, with intel/isa-l#226 being a concern. I've made a comment asking about whether Intel feels this library is safe to use on Mac OS.

Will dig deeper into your issues. It would be helpful if you could try again to install and share the full error message, environment details.

[akotlar]

In intel/isa-l#234 (comment) it appears the mystery is resolved.

The author pushed the necessary fixes to conda-forge. Installing from conda should resolve the issues you were experiencing.

I'm not opposed to moving to a different gzip library, this isn't inspiring any confidence. If there's nothing compelling out there we can just use pigz.

[akotlar]

With intel/isa-l#245, I think I'm convinced to drop this library

[cielavenir]

Can I see what is the conda-forge fix