non è possibile installare matplotlib tramite pip

Question

Sono su Ubuntu 14.04 e ho provato a installare matplotlib tramite pip. Sto usando Python 2.7.6. Tuttavia, ogni volta che corro "sudo pip install matplotlib", ottengo i seguenti errori:

Downloading/unpacking matplotlib 
Downloading matplotlib-1.4.0.tar.gz (51.2MB): 51.2MB downloaded 
Running setup.py (path:/tmp/pip_build_root/matplotlib/setup.py) egg_info for package matplotlib 
    ============================================================================ 
    Edit setup.cfg to change the build options 

    BUILDING MATPLOTLIB 
      matplotlib: yes [1.4.0] 
       python: yes [2.7.6 (default, Mar 22 2014, 22:59:56) [GCC 
         4.8.2]] 
       platform: yes [linux2] 

REQUIRED DEPENDENCIES AND EXTENSIONS 
       numpy: yes [version 1.8.1] 
        six: yes [using six version 1.5.2] 
       dateutil: yes [using dateutil version 2.2] 
       tornado: yes [using tornado version 4.0.1] 
      pyparsing: yes [using pyparsing version 2.0.2] 
       pycxx: yes [Couldn't import. Using local copy.] 
       libagg: yes [pkg-config information for 'libagg' could not 
         be found. Using local copy.] 
Traceback (most recent call last): 
    File "<string>", line 17, in <module> 
    File "/tmp/pip_build_root/matplotlib/setup.py", line 154, in <module> 
    result = package.check() 
    File "setupext.py", line 940, in check 
    if 'No such file or directory\ngrep:' in version: 
TypeError: argument of type 'NoneType' is not iterable 
Complete output from command python setup.py egg_info: 
============================================================================ 

Edit setup.cfg to change the build options 

Ho provato a installare tutte le dipendenze elencate sotto "le dipendenze e le estensioni necessarie", ma ho ancora ottenere lo stesso errore.

Answer 1

Stavo vedendo lo stesso messaggio di errore e l'installazione delle dipendenze menzionate in questo post Pip install Matplotlib error with virtualenv risolto il problema per me.