2009/7/20 Jonathan Underwood <jonathan.underwood(a)gmail.com>:
When building emacs add ons, it's necessary to install the byte
compiled (*.elc) files with -p so that when both the uncompiled
(*.el)and byte compiled files are installed emacs will read the byte
compiled sources - emacs looks at the timestamps of both the el and
elc and loads the elc if it's mtime is later than the .el. Not using
-p often results in emacs disregarding the elc file if the el source
file is installed, negating the usefulness of byte compilation.
Um, sorry, I got that backwards - the non byte compiled .el files need
to be installed with -p, sorry. But you get the point.