Hi all,
    I am using emacs 24.5 (shipped with Ubuntu 16.04 LTS). When I try to
switch to org release 9.0 from git repos, emacs hangs when starting up,

This is what I did for switching to release_9.0

git clone git://orgmode.org/org-mode.git
cd org-mode
git checkout release_9.0
make autoloads

My .emacs is only two lines as follows, and I remove .emacs.d completely to
rule out any possible interactions with other packages,

(add-to-list 'load-path "~/org-mode/lisp")
(add-to-list 'load-path "~/org-mode/contrib/lisp" t)

By searching this list, I've found other people experiencing hanging
problems. My case is more dramatic, it always happen, even when I try to
open  an empty org file. Everything seems good for release_8.3.6. The
changes introducing in  release_9.0 seems to cause the hanging problem. Any
suggesting in how to track down the problem?

Shiyuan