Subject: Re: [X2Go-Dev] Bug#77: Fwd: Bug report, unknown package: X2Go corrupts CygWin

From: Stefan Baur <[email-masked]>
Date: Thu, 06 Dec 2012 12:29:39 +0100

Am 06.12.2012 09:58, schrieb Anders Hallström:
[...]

> What happens is that directories from the X2Go installation are
> suddenly mounted as /etc and /bin in CygWin.
> Since fundamental commands such as "/bin/ls" are thereby missing,
> nothing works.

[...]

> After this fix, I can still use X2Go without problems and without
> the mounts coming back, so I just cannot see why the mounts were
> necessary in the first place.
>
> Sometimes, however, the harmful mounts do come back.
> I cannot pinpoint exactly when this happens,
> but at least it is not every time I restart the computer and not every
> time I run X2Go.
>
> Is this known?
> Could some developer explain what is happening?

Well, X2Go uses some Cygwin code for its Windows client.
I've seen weird things happen before when two applications brought their 
own set of Cygwin libraries and they belonged to different versions, 
maybe this is a similar issue.
Probably something like whoever loads cygwin1.dll first "wins", the 
other application is blocked from loading its own version of cygwin1.dll 
and just has to make do with whatever cygwin1.dll is already in memory. 
  After that, it's either an application from the old Cygwin failing 
because the newer cygwin1.dll is doing something unexpected, or it's a 
new application failing because the old cygwin1.dll doesn't offer the 
function that it is expecting.

So, to debug this issue, it would be interesting to see what happens 
when you first run X2GoClient and keep it in the background, then try to 
rund your old Cygwin applications, and what happens when you run your 
old applications first (keeping at least one window of them open) and 
start X2GoClient afterwards.
Also, be aware that it is wrong to assume that all X2Go tasks have been 
terminated just because you don't see an X2Go icon in your task bar. 
Running task manager after closing X2GoClient, you may still encounter a 
running pulseaudio, sshd and/or vcxsrv on your Windows client.
If you see these, terminete them from within task manager before running 
your old cygwin applications and see if that helps.
I'm not suggesting that this is the solution to your problem, but I am 
sure the results will be helpful for the devs to pinpoint the issue.

-Stefan