the contrib/ subdir in the official org-mode distribution holds various "contributed" codes closely related to org-mode, but is left uninstalled when using their Makefile for system-wide installation Reproducible: Always Steps to Reproduce: is it possible to add a use flag "contrib" and have the contrib subdir installed when it's set?
We cannot simply install the complete contrib directory since it contains some non-lisp files. Also the bundled htmlize.el is available as a separate package app-emacs/htmlize, so this file must be excluded from installation. AFAICS, all other lisp files in contrib could just be byte-compiled and installed in site-lisp/org-mode/ Not sure what should be done with babel/library-of-babel.org and with the files in the scripts/ subdirectory.
Fixed in org-mode-7.3. Sorry for the long delay. With USE="contrib", the Emacs Lisp files from contrib are now installed in ${SITELISP}/${PN}/contrib. Everything else goes to /usr/share/doc/${PF}/contrib. The contributed Lisp files are not being byte-compiled, because compilation fails for some of them. Probably because of missing dependencies, but I haven't further investigated it.
