Hi all, I have learned (thanks to the el-get developers) that org-mode uses with-eval-after-load, which was added in Emacs 24.4. (See discussion [1].) I confirmed that the master branch of org-mode loads (via el-get) successfully in 24.4.1 and fails to load in 24.3.1. I'm not sure what the compatibility policy is in this project, and whether or not this deserves a fix. I personally can work around this by building Emacs from source on older machines, but I will need to do this on every Ubuntu 14.04 machine I use. [1]: https://github.com/dimitri/el-get/issues/2559#issuecomment-322881981 On Tue, Aug 15, 2017 at 1:10 PM, Kaushal Modi wrote: > On Tue, Aug 15, 2017 at 3:48 PM Elliott Slaughter < > elliottslaughter@gmail.com> wrote: > >> Actually, the backtrace goes through the el-get loaddefs file, so maybe >> something is going wrong there. Let me check with the el-get developers and >> see if they know what is going on. >> > > Yes, that's very likely. I have been building Org from master branch and > it has been working fine. > > C-h v org-src-lang-modes tells that it is defined in org-src.el. > > So you probably have a mixed installation where an old org-src.el is > loaded which doesn't have that variable defined. > > (I had recently written about how to install the development version of > Org without causing mixed installations: https://scripter.co/building- > org-development-version/ .) > > -- > > Kaushal Modi > -- Elliott Slaughter "Don't worry about what anybody else is going to do. The best way to predict the future is to invent it." - Alan Kay