robotpkg

I also had to add a patch to omniORB for python 3, as explained here: http://www.omniorb-support.com/pipermail/omniorb-list/2019-May/032063.html

While here, here is a trivial one: https://github.com/nim65s/robotpkg/commit/257d1d36903da375911a515b9f1627fc2d2cba7b

On Friday 10 May 2019, at 11:08, Guilhem Saurel wrote:

As omniORB & omniORBpy are available on Ubuntu only for python2

AFAICT, omniidl uses python3 on Ubuntu 18:
% head -1 /usr/bin/omniidl
#!/usr/bin/python3

(they both have files in ${PYTHON_SITELIB}), I suggest to add a
PKGTAG.python to their name, to provide a Python 3 binary version

At least for omniORB, this is not a good idea: the python dependency
is internal and should not be exposed to other packages (otherwise it
would impose to use the same python version as omniORB for all
dependent packages). And according to the history of omniORBpy in
robotpkg, the same applies, although it's less clear to me.

What should be tested properly is "can omniidl generate python code
for any version, when it is itself built with python2 or python3".

Another strategy could be to force python3 for omniORB{,py}, as
python2 will disappear soon anyway... Then I guess that the generated
code must work for any python version.

Still, I was trying to set PREFER.omniORB = robotpkg when we are on
ubuntu and on python 3, so I tried in
0730604de8f6510f62177c6b120a5029e8a0ea37 with :

 ifeq
> (Ubuntu,${OPSYS})
>   ifneq (,$(filter python34 python35 python36 python37,${DEPEND_USE}))
>     PREFER.omniORB?=    robotpkg
>   endif
> endif
> 

Since omniorb{,py} are both available on ubuntu, I would not recommend
to use PREFER = robotpkg by default. This is always confusing and
error prone to have local packages when system ones are present ...
Of course you can set it in your robotpkg.conf

But it doesn't seem to work, as I had to add PRFER.omniORB=robotpkg to
my robotpkg.conf.

No, probably because at the time this file is included, the python
dependency has not been parsed yet. Something that would work would
be :
PREFER.omniORB?= $(if $(filter pythonXX,${DEPEND_USE}),robotpkg,system)

Contrary to "ifeq" statements that are eval'ed immediately, make
$(if ..) function is eval'ed like variables, when they are expanded.

AFAICT, omniidl uses python3 on Ubuntu 18:
% head -1 /usr/bin/omniidl
#!/usr/bin/python3

Right now, if I use ubuntu 18.04's omniORB / omniORBpy, I can compile py36-qt4-gepetto-viewer-corba. Omniidl, which is used to generate bindings, is a software written in python, and internally uses python 3, yes, but it could be written in any other langage and this would not make any difference for the generated files.

But then, we need to use those bindings. And inside those, we can find:

import omniORB

And on Ubuntu 18.04, dpkg -L python-omniorb shows stuff only in /usr/lib/python2.7/dist-packages/omniORB. And Ubuntu 18.04 doesn't provide a python3-omniorb package.

So when I try to use py36-qt4-gepetto-viewer-corba, I get the following error:

ModuleNotFoundError: No module named 'omniORB'

And building robotpkg's omniORBpy with python3 correctly installs files in a PYTHON_SITELIB for python 3.

Maybe I should have started by explaining that I got this error.

On Monday 13 May 2019, at 11:58, Guilhem Saurel wrote:

But then, we need to use those bindings. And inside those, we can
find:

 import omniORB 

OK, now I understand.

I pushed an intermediate solution: omniORB does not expose python, so
it's not py-prefixed. Only py-omniORBpy needs it.
I tested it quickly on ubutu 18.04, it seems OK.

Yes, omniORBpy is enough. Thanks !