fix building with python2 and python3

[mikhailnov]

I wanted to build mlt with both python2 and python3 for ROSA Linux and had to patch like this to allow this to be done.
https://abf.io/import/mlt/commit/eff21006ee45d596cf4456ff2469f51f5d55cde9

[ddennedy]

I hope it works well enough for all.

[sergiomb2]

Hi,
I have another suggestion which I think is better, the line at the end [1]

[1]

export PYTHON_INCLUDE=`"$PYTHON" -c "from sysconfig import get_paths; print(get_paths()['include'])"`

[ddennedy]

@sergiomb2 why? Is python[23]-config --includes broken on your distro? Can you cite official documentation to support your claim?

[mikhailnov]

Hi, I have another suggestion which I think is better final line [1] [1] |export PYTHON_INCLUDE=`"$PYTHON" -c "from sysconfig import get_paths; print(get_paths()['include'])"` |

This works incorrectly on Ubuntu 19.04 and Python 2: user@pay2:~$ python -c "from sysconfig import get_paths; print(get_paths()['include'])" /usr/local/include/python2.7 There is nothing in /usr/local/include/python2.7, system-wide prefix is /usr, not /usr/local This gives correct results on ROSA: rosa-2016 ~ # python -c "from sysconfig import get_paths; print(get_paths()['include'])" /usr/include/python2.7 But note that python[23]-configs gives ready to use CFALGS: rosa-2016 ~ # python3-config --includes -I/usr/include/python3.5m -I/usr/include/python3.5m rosa-2016 ~ # python3-config --libs -lpython3.5m -lpthread -ldl  -lutil -lm rosa-2016 ~ # Using your method will require constructing (guessing!) CFLAGS manually. Output of python[23]-config may be different on different OSes, for eample note --ldflags on DragonFlyBSD and compare them with GNU/Linux ROSA and Ubuntu above: [root@nas-dfly ~]# python3-config --includes -I/usr/local/include/python3.6m -I/usr/local/include/python3.6m [root@nas-dfly ~]# python3-config --ldflags  -L/usr/local/lib -lpython3.6m -lintl -ldl -L/usr/local/lib -lintl -lutil -lm  -Wl,--export-dynamic [root@nas-dfly ~]# python-config has given us ready to use working CFLAGS, and we do not have to guess them.

[sergiomb2]

here [1] is the problem when PYTHON_INCLUDE=-I/usr/local/include/python3.6m -I/usr/local/include/python3.6m .
Notes: ubuntu is bronken and I use "${PYTHON}-config" --ldflags .
But since we are talking I propose copy python to python3 and have 2 directories like I do in Fedora [2]

[1]
-c -I../.. -I$PYTHON_INCLUDE

[2]
https://src.fedoraproject.org/rpms/mlt/blob/master/f/mlt.spec#_174

[sergiomb2]

note that all swig/python/*.py have she bangs to one python version , for example [1]

[1]
https://github.com/mltframework/mlt/blob/master/src/swig/python/codecs.py#L1

[mikhailnov]

07.11.2019 12:28, Sérgio Basto пишет:

here [1] is the problem when PYTHON_INCLUDE=-I/usr/local/include/python3.6m -I/usr/local/include/python3.6m .

I don't understand what the problem is. How do you get /usr/local when building a distro package in Fedora?!

Notes: ubuntu is bronken and I use "${PYTHON}-config" --ldflags .
But since we are talking I propose copy python to python3 and have 2 directories like I do in Fedora [2]

[1]
-c -I../.. -I$PYTHON_INCLUDE

[2]
https://src.fedoraproject.org/rpms/mlt/blob/master/f/mlt.spec#_174

That is a hack. ( cd src/swig/python3; export PYTHON=python2; ./build ) how I do in ROSA (https://abf.io/import/mlt/blob/rosa2019.1/mlt.spec#lc-211) is a much shorter and because of this more reliable solution than yours in Fedora, at least I believe so.

note that all swig/python/*.py have she bangs to one python version , for example [1]

Good catch... We should fix it

[mikhailnov]

Shebang is not a problem because it does not exist in mlt.py which is the only *.py file being installed. But I had already written a Makefile capable of fixing shebangs before I noticed that shebang is not a problem, sent it in #495

[sergiomb2]

my propose #496

[ddennedy]

But since we are talking I propose copy python to python3 and have 2 directories like I do in Fedora [2]

No, python2 is no longer supported. Now, I regret accepting the change that restores support for it in MLT. if you need it in your distro, patch the source for your package and do not try to upstream it - at least for this package.

note that all swig/python/*.py have she bangs to one python version
Good catch... We should fix it

No, we should not. If you want to use the example python script with python 2.x, then invoke it with that interpreter or edit the example.

-I$PYTHON_INCLUDE is obviously a problem since the output of python3-config --includes includes the -I flags.

[sergiomb2]

OK , no problem , we in Fedora + RPMFusion have one python-mlt client which is Flowblade .
Flowable will have an python3 version before end of the year [1] , and that is why I'd like have python2 and python3 version to migration be more smooth .

About -I$PYTHON_INCLUDE seems to me we just need remove -I and use just $PYTHON_INCLUDE

Thank you

[1]
jliljebl/flowblade#597

[ddennedy]

About -I$PYTHON_INCLUDE seems to me we just need remove -I and use just $PYTHON_INCLUDE

Yes, I made that change.