Just a heads-up, ebuild-mode-1.61 will enable support for ANSI graphical control sequences in the compilation buffer. Presumably by defining a (trivial) derived mode of compilation-mode, which as its only action does this: (if (fboundp 'ansi-color-compilation-filter) (add-hook 'compilation-filter-hook 'ansi-color-compilation-filter nil t)) Maybe ebuild-run-mode should follow?