Using pydart with dart 6.4?

[anlsh]

I believe that my libdart6-all-dev was upgraded to the 6.4 version recently, and since then whenever I try to import pydart2 I get the following error:

Python 3.5.2 (default, Nov 23 2017, 16:37:01) 
[GCC 5.4.0 20160609] on linux
>>> import pydart2
Traceback (most recent call last):
  File "/home/me/Code/libs/pydart2/pydart2/pydart2_api.py", line 18, in swig_import_helper
    fp, pathname, description = imp.find_module('_pydart2_api', [dirname(__file__)])
  File "/usr/lib/python3.5/imp.py", line 296, in find_module
    raise ImportError(_ERR_MSG.format(name), name=name)
ImportError: No module named '_pydart2_api'

During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/me/Code/libs/pydart2/pydart2/__init__.py", line 5, in <module>
    from . import pydart2_api as papi
  File "/home/me/Code/libs/pydart2/pydart2/pydart2_api.py", line 28, in <module>
    _pydart2_api = swig_import_helper()
  File "/home/me/Code/libs/pydart2/pydart2/pydart2_api.py", line 20, in swig_import_helper
    import _pydart2_api
ImportError: libdart.so.6.3: cannot open shared object file: No such file or directory

I checked my library path with ls /usr/lib/libdart* to confirm that I had the libraries in the first place; I believe that I do in fact have all of the packages,

/usr/lib/libdart-collision-bullet.so
/usr/lib/libdart-collision-bullet.so.6.4
/usr/lib/libdart-collision-bullet.so.6.4.0
/usr/lib/libdart-collision-ode.so
etc...

but as you can see they're all version 6.4.0. I searched a bit in the pydart source for some sort of version flag asking for version 6.3, but I didn't find anything obvious. Is there anything I can do to get pydart to recognize the more recent versions of the libraries?

Note: I already tried building dart's release-6.3 branch from source and linking the output libraries to my path; while this does solve the library versioning issues and allows me to import pydart2 normally, there are still some problems- for instance, loading .skel files gives me errors concerning segfaults and stack smashing which I was definitely not running into before. I'm not sure what's causing these errors, therefore I was hoping to rely on the prebuilt packages.

Unfortunately, I can't figure out how to install the v6.3 packages either- the only package with that version from the ppa is 6.3.0.ppa2~zesty, but doing a

sudo apt-get install libdart6=6.3.0.ppa2~zesty 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Version '6.3.0.ppa2~zesty' for 'libdart6' was not found

Fails with the above error. In fact, the only version that the ppa seems to provide is 6.4

apt-cache madison libdart6                     
libdart6 | 6.4.0.ppa1~xenial | http:https://ppa.launchpad.net/dartsim/ppa/ubuntu xenial/main amd64 Packages

[erwincoumans]

I had a similar issue, resolved by adding this to ~/.bashrc

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/lib:/usr/lib:/usr/local/lib