Returned non-zero exit status 1 while trying ./letsencrypt-auto --help

hi,
i keep receiving thiss error “returned non-zero exit status 1” while i try to do this ./letsencrypt-auto --help

Even when i trype this ./letsencrypt-auto --apache -d example.com i keel receiving same error. Here is the full error: Installing Python packages…
Traceback (most recent call last):
File “/tmp/tmp.hsCloWes50/pipstrap.py”, line 146, in
exit(main())
File “/tmp/tmp.hsCloWes50/pipstrap.py”, line 133, in main
shell=True)
File “/usr/local/lib/python2.7/subprocess.py”, line 573, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command ‘pip install --no-index --no-deps -U /tmp/pipstrap-FhnXLs/pip-8.0.3.tar.gz /tmp/pipstrap-FhnXLs/setuptools-20.2.2.tar.gz /tmp/pipstrap-FhnXLs/wheel-0.29.0.tar.gz’ returned non-zero exit status 1

any idea…? Thanks