Re: Boost cannot find numpy37 on Dockerized Ubuntu 20.04

From: Roy de Bokx (rdebokx1990_at_[hidden])
Date: 2021-02-19 10:46:59

Op wo 17 feb. 2021 om 20:30 schreef Anonymous Maarten <
anonymous.maarten_at_[hidden]>:

> Thanks for your answer Maarten!
>> Please bare with me as I'm a little new to this. Is there some way I can
>> change the interpreter that is used for installing boost? Or do you think
>> that adapting the --prefix flag may also work?
>>
>
> When using the pre-built boost packages of a linux distribution (ubuntu),
> you're generally stuck with the versions/options that its packagers have
> chosen.
> A distribution freezes versions to make a more robust experience.
>
> Adding a `--prefix` will not help because, first of all, it's not a valid
> gcc option, and second, ubuntu 18.04 does not provide a
> libboost-python-py37 shared/static library.
> Do you really need python 3.7? Doesn't 3.6 suffice?
>

Thanks! This helped me understanding the issue a bit further. I think 3.6
should suffice indeed, so I tried using 3.6 by removing the 3.7
installation from the Dockerfile and using the -lboost_numpy3 flag instead.
It seems I ran into some linking issue after this. It was able to find the
right numpy3.so and libboost_python3-py36.so, but I'm getting a lot of
errors like these:

//usr/lib/x86_64-linux-gnu/libboost_numpy3.so: undefined reference to
`PyExc_ValueError'

//usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined
reference to `PyLong_AsLong'

//usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined
reference to `PyNumber_InPlaceFloorDivide'

//usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined
reference to `PyBool_Type'
etc...

I've pasted the full docker file and logs in
https://github.com/boostorg/boost/issues/462
Thanks again for any help.

>
> If you really want to use Boost.Python + python 3.7, you can do 2 things:
> - stay on ubuntu bionic and build boost yourself (or use an alternative
> c/c++ package manager, e.g. [conan](https://conan.io/) has a [boost
> package](https://conan.io/center/boost))
> - more to a more recent ubuntu release. e.g. ubuntu 20.10 has python 3.8:
> https://packages.ubuntu.com/groovy/amd64/libboost-python1.71-dev/filelist
>
I've also given 20.10 a try, however I ran into the same linking issues as
mentioned above.

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