Re: Branching based on Python version (was [PATCH 2/6] gnu: add python-sqlparse and python2-sqlparse)

[Ludovic Courtès]

Leo Famulari <address@hidden> skribis:

> On Thu, Apr 21, 2016 at 09:19:49PM +0200, Hartmut Goebel wrote:
>> * gnu/packages/python.scm (python-sqlparse) (python2-sqlparse):
>>   New variables.
>
>> +    (arguments
>> +     `(#:phases
>> +       (modify-phases %standard-phases
>> +         (replace 'check
>> +           (lambda* _
>> +             ;; setup.py-integrated 2to3 only affects the build files, but
>> +             ;; py.test is using the source files. So we need to convert 
>> them
>> +             ;; manually.
>> +             (if (zero? (system* "python3"))
>> +                 (system* "2to3" "--no-diff" "-wn" "sqlparse" "tests")
>> +                 #t)
>> +             (zero? (system* "py.test")))))))
>
> I think there must be a better way to do this conditional, but I'm not
> sure what it is. Does anyone have any ideas?

(guix build python-build-system) includes ‘get-python-version’, which
could be used for this purpose.

But I think the above is acceptable here (I’d use ‘when’ instead of the
one-armed ‘if’, but that’s purely cosmetic.)

Thanks,
Ludo’.