Python3 modules are not installed in the right path

[Shu Hung (Koala)]

[Note: this might be a bug in autoconf rather than automake, I'm not entirely sure]

On Ubuntu (and I think also on Debian), Python3 modules are installed in /usr/lib/python3/dist-packages

However, that's different from the upstream path, which is /usr/lib/python3.3/site-packages

Python3 modules building with the Autotools will get installed in the upstream-preferred path, and as a result, Python3 won't find them.

Here is a way to reproduce it:

1. First, install libcangjie from Git:

    git clone git://github.com/Cangjians/libcangjie
    cd libcangjie
    ./autogen.sh --prefix=/usr && make && sudo make install

2. Now, install pycangjie:

    git clone git://github.com/Cangjians/pycangjie
    cd pycangjie
    ./autogen.sh --prefix=/usr && make && sudo make install

(you might need to install some dependencies, like libsqlite3-dev, python3-de and cython)

Now, observe how the module was installed in /usr/lib/python3.3/site-packages/cangjie, where Python3 won't find it.

This installation path is not hardcoded in the pycangjie build process, it is **automatically discovered by the autotools**.

If Ubuntu (or is it Debian?) decides to change where Python3 modules are installed, then shouldn't it also try to ensure that they actually get installed there?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Shu Hung (Koala) (koalay)]

From *Deviations_from_upstream* in Debina's Python wiki page
https://wiki.debian.org/Python#Deviations_from_upstream

-----------

* dist-packages instead of site-packages. Third party Python software installed from Debian packages goes into dist-packages, not site-packages. This is to reduce conflict between the system Python, and any from-source Python build you might install manually.

-----------

A more detailed discussion on the same issue can be found here in Debian's bug tracker:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=765022#30

That says Debian deliberately treat .deb python packages and manually installed python modules differently. They changed the stock Debian Pythons' module path from `site-packages` to `dist-packages`. So the stock Python uses modules only from DEB sources (installs to `dist-packages`) and not from easy_install or otherwise compiled (installs to `site-packages`).

Automake either doesn't care or horner the management ideal. They only support you to install your python library into `site-packages` so it doesn't overwrite the packages you installed with .deb.

If Automake provide config directive to override `pyexecdir` and `pythondir`, it would be a much better tool for system package developers (e.g. Python based ibus engine developer) for proper testing. I found no such option yet.