Before anything else, make sure you're up to date on all the dependencies required. The installation process is described on the Building page.
Please add to this page if you come across new issues and find their solutions.
Issues
Package oniguruma was not found in the pkg-config search path
You might be missing the oniguruma.pc file. You can try putting it in /usr/lib/pkgconfig or set the PKG_CONFIG_PATH environment variable before doing go get.
export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$GOPATH/src/github.com/limetext/rubex
Package python3.4 was not found in the pkg-config search path
Make sure you have python3.4 installed!
On Ubuntu:
sudo add-apt-repository ppa:deadsnakes
sudo apt-get update
sudo apt-get install python3.4 python3.4-dev
It builds fine, but crashes when I try to start it
If the log shows something like
[09:31:42 UTC 2015/08/04] [EROR] (log.(*logger).Error:5) Unable to load colorscheme definition: open ../packages/themes/TextMate-Themes/Monokai.tmTheme: no such file or directory`
make sure you init and update the git submodules.