I'm going to do something potentially rude and comment on this without having read the entire thread.
On Thu, Oct 11, 2012 at 10:39 PM, Gregory M. Turner <g...@malth.us> wrote: > Anyhow one thing I have figured out is how things can work correctly on > Linux wihtout -L.: on Linux, the python plugins aren't actually linked > against libpython.so! Python can be built with and without a shared library (libpythonx.y.so). If the shared library is built the interpreter executable is linked against it (of course), and normally so are the extension modules. This is useful because it makes the linker do the right thing for applications that embed python (and end up loading libpythonx.y via dlopen). If the shared library is not built extension modules cannot link against it, and the python executable itself exports the relevant symbols. So on a normal shared python build extensions should end up linked against libpythonx.y.so. However, at least one popular distro and presumably most of its derivatives (Debian) has a system python built without the shared library, plus the shared library built separately, for use by applications that embed python. I am not entirely sure why they still do this (if I understand correctly it was originally done for performance reasons, but I'm not sure if they've checked those are still valid). Their extension modules cannot link to libpythonx.y: their python interpreter executable provides the same symbols libpythonx.y provides, so loading such an extension module into the regular interpreter would result in collisions. The reason I mention this is Gentoo's python is built with the shared library, so on Gentoo your extensions *should* end up linked to libpythonx.y (if they use a more or less standard build system, at least). If yours are not I'm curious what happened, and would appreciate it if you gave me some more information off-list (marienz on freenode or email). -- Marien Zwart.
