Homebrew users who get error regarding xcb-shm

[naturalethic]

The fix is to add this to your bash profile / environment:

export PKG_CONFIG_PATH=/opt/X11/lib/pkgconfig

(Perhaps put this somewhere in the readme)

Homebrew/legacy-homebrew#14123

[nucleardreamer]

For anyone new following this problem from installing xquartz, and then cairo from homebrew make sure to add the PKG_CONFIG_PATH=/opt/X11/lib/pkgconfig line to either ~/.bash_profile or ~/.bashrc depending on what you have setup.