How can I correct a corrupted $PYTHONPATH?

Question

When trying to launch Mercurial(hg) after a restart in my Ubuntu 9.10 Linux Box I got following message:

      abort: couldn't find mercurial libraries in [/usr/bin /usr/local/lib/python2.6/dist-packages/vipy-0.4-py2.6.egg /usr/local/lib/python2.6/dist-packages/nose-0.11.1-py2.6.egg /usr/local/lib/python2.6/dist-packages/rope-0.9.2-py2.6.egg /usr/local/lib/python2.6/dist-packages/Sphinx-0.6.3-py2.6.egg /usr/local/lib/python2.6/dist-packages/django_html-0.0.1-py2.6.egg /usr/local/lib/python2.6/dist-packages/html5lib-0.11.1-py2.6.egg /home/kenny /home/kenny/Projects/soclone-read-only /home/kenny/python/Django /home/kenny/python/pysmell /home/kenny/python/Django/ropemode /home/kenny/python/Django/rope /home/kenny/python/lib /usr/lib/python2.6 /usr/lib/python2.6/plat-linux2 /usr/lib/python2.6/lib-tk /usr/lib/python2.6/lib-old /usr/lib/python2.6/lib-dynload /usr/local/lib/python2.6/dist-packages]

      (check your install and PYTHONPATH)

Mysteriously other Python programs don't find their modules, including django-admin, bzr, BUT surprisingly the Python interpreter itself is launching.

Here you can find my current sys.path:

  ['', '/usr/local/lib/python2.6/dist-packages/vipy-0.4-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/nose-0.11.1-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/rope-0.9.2-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/Sphinx-0.6.3-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/django_html-0.0.1-py2.6.egg', '/usr/local/lib/python2.6/dist-packages/html5lib-0.11.1-py2.6.egg', '/home/kenny', '/home/kenny/Projects/soclone-read-only', '/home/kenny/python/Django', '/home/kenny/python/pysmell', '/home/kenny/python/Django/ropemode', '/home/kenny/python/Django/rope', '/home/kenny/python/lib', '/usr/lib/python2.6', '/usr/lib/python2.6/plat-linux2', '/usr/lib/python2.6/lib-tk', '/usr/lib/python2.6/lib-old', '/usr/lib/python2.6/lib-dynload', '/usr/local/lib/python2.6/dist-packages']

Does anyone know how to resolve this issue?

I know this is no programming question in specific, but it disallows me to program, so I beg your comprehension!

Thanks in advance.

Answer 1

Try this:

update-python-modules -p

(might need to sudo that...) Source: http://hg.opensource.lshift.net/mercurial-server/rev/32dba1a70a54

Answer 2

Is mercurial located in one of the library installation paths (dist-packages or site-packages)? You can use the find tool to look for it?

Did you have luck installing small libraries and access them from Python on this machine?

Answer 3

You could try to reinstall affected Python programs with aptitude:

sudo aptitude reinstall mercurial

Answer 4

All of the sites I've googled for this say that your PYTHONPATHis set wrong. The code that you are hitting in mercurial appears to be this:

try:
    from mercurial import demandimport; demandimport.enable()
except ImportError:
    import sys
    sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
                     ' '.join(sys.path))
    sys.stderr.write("(check your install and PYTHONPATH)\n")
    sys.exit(-1)

So where is demandimport on your machine? On my windows box, it is here:

>>> from mercurial import demandimport
>>> demandimport.__file__
'C:\\Python26\\lib\\site-packages\\mercurial-1.4.1-py2.6-win32.egg\\mercurial\\demandimport.pyc'

And that works because I have mercurial in my PYTHONPATH:

>>> import sys
>>> for s in sys.path:
...     print s
...
# Other crud deleted...
C:\Python26\lib\site-packages\mercurial-1.4.1-py2.6-win32.egg
C:\Windows\system32\python26.zip
C:\Python26\DLLs
C:\Python26\lib
C:\Python26\lib\plat-win
C:\Python26\lib\lib-tk
C:\Python26
C:\Python26\lib\site-packages

Your PYTHONPATH makes no mention of mercurial. At a guess, I would add this to your PYTHONPATH:

/usr/local/lib/python2.6/site-packages

and I would re-install mercurial from make. That advice worked well here.

Edit: And on my Ubuntu 9.10 box, I got these results:

>>> import mercurial
>>> mercurial.__file__
'/usr/lib/pymodules/python2.6/mercurial/__init__.pyc'
>>> import sys
>>> for s in sys.path:
...     print s
...

/usr/local/lib/python2.6/dist-packages/pip-0.6.1-py2.6.egg
/usr/local/lib/python2.6/dist-packages/virtualenv-1.4.3-py2.6.egg
/usr/lib/python2.6
/usr/lib/python2.6/plat-linux2
/usr/lib/python2.6/lib-tk
/usr/lib/python2.6/lib-old
/usr/lib/python2.6/lib-dynload
/usr/lib/python2.6/dist-packages
/usr/lib/python2.6/dist-packages/PIL
/usr/lib/python2.6/dist-packages/gst-0.10
/usr/lib/pymodules/python2.6
/usr/lib/python2.6/dist-packages/gtk-2.0
/usr/lib/pymodules/python2.6/gtk-2.0
/usr/local/lib/python2.6/dist-packages
/usr/local/lib/python2.6/dist-packages/PIL

And this makes me think the problem is that this is missing for you: /usr/lib/pymodules/python2.6.

Answer 5

Thanks for the effort to all of you.

I've solved the problem thanks to hughdbrown. hughdbrown, you've made me realize that I commited a typo when defining doing $PYTHONPATH; instead of adding the path /usr/lib/pymodules/python2.6, I wrote /usr/lib/pymodules/ so python couldn't import the libraries... However, I corrected it and I'm glad to see Mercurial and Co. work again.

The only strange thing is, WHY it changed... Well, I'll be knowing from now on what to do.