bug#36623: [PATCH] gnu: gdal: add python support

[宋文武]

Arne Babenhauserheide <address@hidden> writes:

> 宋文武 <address@hidden> writes:
>
>> Arne Babenhauserheide <address@hidden> writes:
>>
>>> Hello Ludo`,
>>>
>>> Ludovic Courtès <address@hidden> writes:
>>>
>>>>> validating RUNPATH of 6 binaries in 
>>>>> "/gnu/store/q9sb0wv41ig429f1m1xspg22xm8pwpwh-gdal-2.2.4/lib"...
>>>>> /gnu/store/q9sb0wv41ig429f1m1xspg22xm8pwpwh-gdal-2.2.4/lib/python3.7/site-packages/osgeo/_gdal.cpython-37m-x86_64-linux-gnu.so:
>>>>> error: depends on 'libgdal.so.20', which cannot be found in RUNPATH
>>>>> ("/gnu/store/b7fqhszxl02g6pfm3vw6b3cjz472qrly-python-3.7.0/lib"
>>>>> "/gnu/store/h90vnqw0nwd0hhm1l5dgxsdrigddfmq4-glibc-2.28/lib"
>>>>> "/gnu/store/4sqps8dczv3g7rwbdibfz6rf5jlk7w90-gcc-5.5.0-lib/lib"
>>>>> "/gnu/store/4sqps8dczv3g7rwbdibfz6rf5jlk7w90-gcc-5.5.0-lib/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/../../..")
>>>>
>>>> I’m not familiar with Cython so I don’t know how this was handled
>>>> before.  However, to me, it indicates that the resulting binaries are
>>>> unlikely to work.
>>>>
>>>> Namely, Python would dlopen “_gdal.cython*.so”, and that would fail to
>>>> find ‘libgdal.so’.
>>
>>>>
>>>> Thoughts?
>>>
>>> Yes: It does work. But I don’t know why.
>>
>> This is because the _gdal.cython*.so don't have rpath to the "lib"
>> directory, where libgdal.so will going.
>>
>>>
>>> Cython runs at compile-time to generate c-code that acts as interface
>>> for Python. Given the paths in here, this needs gdal already installed
>>> in the runpath where it seems to be missing during validation.
>>>
>>> How can we fix that?
>>
>> I think cython (which compile .py files to .c files) is not here..  It
>> has python C libraries generated by swig.
>>>
>>> Best wishes,
>>> Arne
>>
>> In the end the python bindings for gdal can be build seperated (which
>> handle the missing rpath to libgdal nicely), and I prefer this way:
>>
>> From 09254f646b948a5603b2b3dcb99a7f2f6ad0c8de Mon Sep 17 00:00:00 2001
>> From: =?UTF-8?q?=E5=AE=8B=E6=96=87=E6=AD=A6?= <address@hidden>
>> Date: Sat, 20 Jul 2019 22:39:33 +0800
>> Subject: [PATCH] gnu: Add python-gdal.
>>
>> For <https://issues.guix.gnu.org/issue/36623>, thank to Arne Babenhauserheide
>> for the original patch.
>>
>> * gnu/packages/geo.scm (python-gdal): New package.
>> ---
>>  gnu/packages/geo.scm | 19 +++++++++++++++++++
>>  1 file changed, 19 insertions(+)
>>
>> diff --git a/gnu/packages/geo.scm b/gnu/packages/geo.scm
>> index e4b6a262c7..8005c46129 100644
>> --- a/gnu/packages/geo.scm
>> +++ b/gnu/packages/geo.scm
>> @@ -604,6 +604,25 @@ utilities for data translation and processing.")
>>                 ;; frmts/mrf/libLERC
>>                 license:asl2.0))))
>>  
>> +(define-public python-gdal
>> +  (package (inherit gdal)
>> +    (name "python-gdal")
>> +    (build-system python-build-system)
>> +    (arguments
>> +     '(#:tests? #f                      ; no tests
>> +       #:phases
>> +       (modify-phases %standard-phases
>> +         (add-before 'build 'chdir
>> +           (lambda _
>> +             (chdir "swig/python")
>> +             #t)))))
>> +    (native-inputs '())
>> +    (propagated-inputs
>> +     `(("python-numpy" ,python-numpy)))
>> +    (inputs
>> +     `(("gdal" ,gdal)))
>> +    (synopsis "GDAL (Geospatial Data Abstraction Library) python 
>> bindings")))
>> +
>>  (define-public postgis
>>    (package
>>      (name "postgis")
>
> Wow, that looks pretty good!
>
> Thank you for fixing up my patch!
>

Sure, pushed!