Error installing scrapy 0.22 (on Ubuntu 12.04): "gcc" failed with exit status 1

Question

When trying to install Scrapy from the command line using pip
sudo pip install scrapy
I get the following error:
error: command 'gcc' failed with exit status 1

After looking at a few lines in the error output, I see that the error occurs when I try to install the cryptography package, which seems to be a pyOpenSSL dependency

I tried installing pyOpenSSL on my own and it gives the same error. After reading the error output, I found that the probable cause of this error is a missing file:

ffi.h: No such file or directory

How do I get out of here?

Answer 1

Try

sudo apt-get install libffi libffi-dev