python setup: changing library path

stateless · 02-01-2013, 07:47 PM

Hi. I'm trying to install a python modules that is trying to build something using gcc, but it fails with:

Code:

/usr/bin/ld: cannot find -lpython2.7

libpython2.7.so happens to be in an unusually place on my system. I set LD_LIBRARY_PATH to exactly the correct place, but setup.py doesn't seem to care. How to I tell setup.py where it is supposed to find its shared libraries?

PTrenholme · 02-10-2013, 04:02 PM

Go to where it normally looks and symlink from there to the actual library location.

stateless · 02-11-2013, 01:07 PM

The problem is that I did a local Python installation on a system on which I don't have admin privileges, so I can't create symlinks in the normal spot. (They were using a really ancient version of Python, and I wanted the latest.) I used Nix to install Python locally, and I know exactly where it put the shared library, but I don't know how to get setup.py to use it.

PTrenholme · 02-12-2013, 01:58 PM

I think that creating a local ~/bin directory an putting the correct value in it might work. You should, of course, make sure that your PATH value starts with ~/bin

Here's the standard values on my (old) laptop, running Fedora 18.

Code:

~ $ type -p python
/usr/bin/python
~ $ file $(type -p python)
/usr/bin/python: symbolic link to `python2'
~ $ file $(type -p python2)
/usr/bin/python2: symbolic link to `python2.7'
~ $ file $(type -p python2.7)
/usr/bin/python2.7: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=0xf872fc2e1f49b9b747a4ebd45265dc72a707cb3e, stripped

stateless · 02-13-2013, 01:17 PM

Quote:

Originally Posted by PTrenholme

I think that creating a local ~/bin directory an putting the correct value in it might work. You should, of course, make sure that your PATH value starts with ~/bin

Here's the standard values on my (old) laptop, running Fedora 18.

Code:

~ $ type -p python
/usr/bin/python
~ $ file $(type -p python)
/usr/bin/python: symbolic link to `python2'
~ $ file $(type -p python2)
/usr/bin/python2: symbolic link to `python2.7'
~ $ file $(type -p python2.7)
/usr/bin/python2.7: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=0xf872fc2e1f49b9b747a4ebd45265dc72a707cb3e, stripped

Maybe I misunderstood your response, but I do not think it addresses my specific problem. I do not have any problems executing my custom version of Python. My PATH is already set correctly for that and the correct binary launches. The problem is that, when I try to build a module using "python setup.py", the setup.py program cannot find the custom version of the libpython2.7.so shared library. I know where it is, and I set LD_LIBRARY_PATH to make it available, but setup.py does not seem to be respecting this.

ntubski · 02-13-2013, 02:10 PM

Based on Tweaking compiler/linker flags, I think if you add

Code:

-L/your/libpython/path/

to the Setup file it should work. Putting that in the CFLAGS environment variable should also work.

It seems like there could be a way to add this setting to some kind configuration file so it will be added automatically, but the docs are somewhat vague about the syntax.