Hang on startup on OS X (GUI only)

[Elliott Slaughter <elliottslaughter@gmail.com>]

(If there is a better place to direct this (e.g. a bug tracker) please let
me know.)

Emacs often hangs on startup on Mac OS X. The hangs are non-deterministic
but frequent (25-50% of runs), consume 100% of CPU, and only happen when
starting Emacs.app with the GUI enabled, never when running in text mode on
the command-line. I have reproduced the hangs with an empty .emacs file and
after having completely removed .emacs.d.

I am using Emacs 24.4 from http://emacsformacosx.com/ , but notably, this
bug has been reported multiple times by users of Homebrew (who either
compile from source or download a binary from Homebrew's own servers):
https://github.com/Homebrew/homebrew/issues/36737
https://github.com/Homebrew/homebrew/issues/25003

I have attached the start of a log from Mac OS X's built-in crash reporter.
I can provide the rest of the report as well, if that would be helpful. (It
contains various stack traces sampled from the unresponsive process.)

Note that while the trace below says that I've installed Emacs from
homebrew, this is the cask version, which is just a proxy for the
emacsformacosx.com version, which is not the same as the Homebrew proper
version (which was the focus of the bug reports above), which is compiled
from source.

Thanks in advance!

===========

Date/Time:       2015-02-15 11:08:40 -0800
OS Version:      10.10.2 (Build 14C109)
Architecture:    x86_64
Report Version:  21

Command:         Emacs-x86_64-10_9
Path:
/opt/homebrew-cask/*/Emacs.app/Contents/MacOS/Emacs-x86_64-10_9
Version:         ??? (???)
Parent:          launchd [1]
PID:             39366

Event:           hang
Duration:        4.00s (process was unresponsive for 176 seconds before
sampling)
Steps:           41 (100ms sampling interval)

Hardware model:  MacBookPro8,2
Active cpus:     8

Fan speed:       4362 rpm

[... file continues for about 1 MB of text ...]

-- 
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