Ubuntu running `pip install` gives error 'The following required packages can not be built: * freetype'
When performing pip install -r requirements.txt, I get the following error during the stage where it is installing matplotlib:
REQUIRED DEPENDENCIES AND EXTENSIONS
numpy: yes [not found. pip may install it below.]
dateutil: yes [dateutil was not found. It is required for date
axis support. pip/easy_install may attempt to
install it after matplotlib.]
tornado: yes [tornado was not found. It is required for the
WebAgg backend. pip/easy_install may attempt to
install it after matplotlib.]
pyparsing: yes [pyparsing was not found. It is required for
mathtext support. pip/easy_install may attempt to
install it after matplotlib.]
pycxx: yes [Couldn't import. Using local copy.]
libagg: yes [pkg-config information for 'libagg' could not
be found. Using local copy.]
freetype: no [pkg-config information for 'freetype2' could
not be found.]
...
The following required packages can not be built:
* freetype
Shouldn't pip install -r requirements.txt also install freetype? How should freetype be installed in Ubuntu 12.04 so it works with matplotlib?
Answer
No. pip will not install system-level dependencies. This means pip will not install RPM(s) (Redhat based systems) or DEB(s) (Debian based systems).
To install system dependencies you will need to use one of the following methods depending on your system.
Ubuntu/Debian:
apt-get install libfreetype6-dev
To search for packages on Ubuntu/Debian based systems:
apt-cache search <string>
e.g:
apt-cache search freetype | grep dev
Redhat/CentOS/Fedora:
yum -y install freetype-devel
To search for packages on Redhat/CentOS/Fedora based systems:
yum search <string>
e.g:
yum search freetype | grep devel
Mac OS X: (via Homebrew)
brew install freetype
To search for packages on Mac OS X based systems:
brew search <string>
e.g:
brew search freetype