no module _sha256 installing cellProfiler

Question

I'm trying to install cellprofiler for developpers on linux and get a "no module named _sha256" error. I looked on a few blogs to find a solutions but nothing worked, can someone help me to fix this?

here's my configuration :

Python 2.7.3 (default, Aug  1 2012, 05:16:07) 
[GCC 4.6.3] on linux2

linux :

uname -m
i686

Distributor ID: Ubuntu
Description:    Ubuntu 12.04.2 LTS
Release:        12.04
Codename:       precise

and here is the error I get:

local@pc-ellenberg23:~/Softwares/cellProfiler/CellProfiler$ make -f Makefile.CP2 PREFIX="${HOME}/usr/cp2"
All pre-checks executed successfully.
export PATH="/home/local/usr/cp2/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/jvm/java-7-openjdk-i386/bin:/usr/lib/jvm/java-7-openjdk-i386/bin:/usr/lib/jvm/java-7-openjdk-i386/bin" && \
                    export LD_LIBRARY_PATH="/home/local/usr/cp2/lib:${LD_LIBRARY_PATH}" && \
                    sh setuptools-0.6c11-py2.6.egg --prefix="/home/local/usr/cp2"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/local/Softwares/cellProfiler/CellProfiler/setuptools-0.6c11-py2.6.egg/setuptools/command/easy_install.py", line 21, in <module>
  File "/home/local/Softwares/cellProfiler/CellProfiler/setuptools-0.6c11-py2.6.egg/setuptools/package_index.py", line 2, in <module>
  File "/home/local/usr/cp2/lib/python2.6/urllib2.py", line 93, in <module>
    import hashlib
  File "/home/local/usr/cp2/lib/python2.6/hashlib.py", line 138, in <module>
    sha224 = __get_builtin_constructor('sha224')
  File "/home/local/usr/cp2/lib/python2.6/hashlib.py", line 66, in __get_builtin_constructor
    import _sha256
ImportError: No module named _sha256
make: *** [/home/local/usr/cp2/bin/easy_install] Error 1

sorry if the error seems silly, i'm new on dealing with error message on linux installations

Thanks you very much

Answer 1

I finally installed it manually, without using their makefile (installing all the dependencies, and executing the cellprofiler.py file. I had to change their code a litle bit (they use the system environment variable and it produces an error (searching my libjvm.so file in the wrong path(i386 instead of i686)) It seems to generate the path for the libjvm.so file automatically from the java_home variable but in my case, the path created was wrong, (generated path : /usr/lib/jvm/java-6-openjdk-i386/jre/lib/i686/server/libjvm.so and the real path was: /usr/lib/jvm/java-6-openjdk-i386/jre/lib/i386/server/libjvm.so) hope this will help if someone has the same problem. Please let me know if someone found the solution for the _sha256 error.

Answer 2

You are missing a library dependency for the hashlib module.

On Ubuntu, you need to install the libsasl2-dev and libssl-dev packages, then recompile (make -f Makefile.CP2 clean; make -f Makefile.CP2 PREFIX="${HOME}/usr/cp2" ) the CellProfiler dependencies.