FW: Firefox 44 on Fedora 23 won't start

[CLOSE Dave]

 -----Original Message-----
From: 	CLOSE Dave
Sent:	Thursday, February 18, 2016 06:17 PM Pacific Standard Time
To:	support-firefox at lists.mozilla.org
Subject:	Re: Firefox 44 on Fedora 23 won't start

I wrote:

> A fresh installation of Firefox 44 on a fresh installation of Fedora
> 23 server edition. All packages installed directly from the Fedora
> repos. According to dnf, there are no missing dependencies. I see the
> same behavior on about 25 new machines.
>
> Starting Firefox from an icon shows an entry in the panel for a few
> seconds, then nothing. Starting it from the command line in a shell
> window returns a new prompt after a few seconds. The exit code is
> zero and there is nothing recorded in syslog or the systemd journal.
> No Firefox window ever appears.
>
> I've also tried adding the -preferences and/or -private switches
> with the same result. The only thing I see strange is a new file in
> the saved-telemetry-pings directory each time I try to start Firefox.
> If FF is trying to use telemetry by default before I get a chance to
> disable it, FF will fail because it will never get through the
> proxy.

Additional information. I have one machine where FF works. This is also
running Fedora 23 but was installed from the live DVD rather than using
PXE as were those which are failing. It has FF 42 rather than FF 44.
Thus far, I've tried these remedies without success.

* Downgrade FF to 42 on a failing machine.

* Compare the list of packages installed on both machines and install on
the failing machine any which were previously only on the working one.
(In fact, the working machine has several hundred /fewer/ packages
installed but had a few extra ones as well.

* Per tjoen's suggestion, verified that both machines have NSS installed
and configured identically. Neither is using LDAP.

In all cases, FF exits with a zero status. I've run both the working and
failing copies under strace and compared the output (there's a lot of
output!). Certainly there are differences but nothing stands out as an
indicator of the problem.

There must be some way to get FF to tell me why it is failing!
-- 
Dave Close