DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 65I7KRuo1154421
Authentication-Results: delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com
Authentication-Results: delorie.com; spf=pass smtp.mailfrom=cygwin.com
DKIM-Filter: OpenDKIM Filter v2.11.0 delorie.com 65I7KRuo1154421
Authentication-Results: delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=LSwPcgGx
X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 47B5F4BA799B
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1781767225;
	bh=pk3YzvxF37M9Kaxb0Zednpi8IVc9EJzbtsiuIrAYGSM=;
	h=Date:Subject:To:References:In-Reply-To:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:
	 From;
	b=LSwPcgGxNEDQ14ZiVgbfVRQNWbhFjoqyqgVjFi4xIDABc0bKVSYj84GjsTQknkuG1
	 C++BQuE0UkB+P5t61ZAFudcEz1RLauOl3tPF/JuO4FzxxYr+8zcozSHRNpTpMdqDYi
	 vxUFeRu/P+8/oUVEOD67TO6GSrj2f9FmmdBczD/c=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A48534BA2E33
ARC-Filter: OpenARC Filter v1.0.0 sourceware.org A48534BA2E33
ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1781767175; cv=none;
 b=UmpEngPOoS2Z6Zw99Nb+00+MwEmycTXRvGASe3sbJLXa9HXncnXYAU9nMGe5DDY/icXnIOD/xVHHgDF1QSJvHIE96Qm1zksE8Q6cLSlXwk6pV0bQr/fCchsCc1sh0NLROBW+SbnoeC0lW+gbk5eDyU8Efjs9VnMtW23XFfJK2RM=
ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key;
 t=1781767175; c=relaxed/simple;
 bh=nPnSBQZQiIbxtVU1dg6P0YDLz61usoXYfa2Srbvl/RY=;
 h=Message-ID:Date:MIME-Version:Subject:To:From;
 b=myXzEOFkQQz8mFUqPRfVxmEx5Cy+dJIDrsbo33voME2+Ex2vn8v6AxITEYKOgOgFTh0ZeDfJiNpxMslWuueWIbyibfjAb8OQKkfyuyIP0MqcB4Dt71SHeEuyYke0Ih26VRpKcvPvo1D6hm3rh8GcJZvRUsWQHN8+cwlB7VoSXBU=
ARC-Authentication-Results: i=1; sourceware.org
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A48534BA2E33
Message-ID: <aa2381ad-c609-40a3-b643-7e67b3b66e1d@maxrnd.com>
Date: Thu, 18 Jun 2026 00:19:38 -0700
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Fwd: BUG?!: Running cygserver switches egid/primary group to
 4095(CurrentSession)
To: cygwin AT cygwin DOT com
References: <CAPJSo4W-MmBMjVDJg3BA1dqJQ_u59srz6+_-3Uti5ktebZ7-Mw AT mail DOT gmail DOT com>
 <CAPJSo4VsSq=a7dSGa17nfy6CEdTfvJuSu_1NT-dGKK+xXSwLaw AT mail DOT gmail DOT com>
 <CAPJSo4V23W3AJHYhtce7hbrm=QtE+vgBqLu8rf+qp63oNuXTyw AT mail DOT gmail DOT com>
 <f3ef6d4e-dc1a-48ad-8711-b57d8b614fbf AT maxrnd DOT com>
 <1341987082 DOT 20260617203636 AT yandex DOT ru>
Content-Language: en-US
In-Reply-To: <1341987082.20260617203636@yandex.ru>
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.30
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Mark Geisert via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Mark Geisert <mark AT maxrnd DOT com>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Errors-To: cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

Hi Andrey,

On 6/17/2026 10:36 AM, Andrey Repin via Cygwin wrote:
> Greetings, Mark Geisert!
> 
>> On 6/8/2026 3:35 PM, Lionel Cons via Cygwin wrote:
>> [...]
>>> If I run without cygserver id -a returns
>>> $ id -a
>>> uid=197620(lcons) gid=197121(Kein)
>>> groups=197121(Kein),197615(docker-users),545(Benutzer),559(Leistungsprotokollbenutzer),4(INTERAKTIV),66049(KONSOLENANMELDUNG),11(Authentifizierte
>>> Benutzer),15(Diese Organisation),113(Lokales
>>> Konto),4095(CurrentSession),66048(LOKAL),262154(NTLM-Authentifizierung),401408(Mittlere
>>> Verbindlichkeitsstufe)
>>>> but if I start cygserver each new session has gid=4095(CurrentSession)
>>> as egid/primary group for new terminals
>>> $ id -a
>>> uid=197620(lcons) gid=4095(CurrentSession)
>>> groups=4095(CurrentSession),197121(Kein),197615(docker-users),545(Benutzer),559(Leistungsprotokollbenutzer),4(INTERAKTIV),66049(KONSOLENANMELDUNG),11(Authentifizierte
>>> Benutzer),15(Diese Organisation),113(Lokales
>>> Konto),66048(LOKAL),262154(NTLM-Authentifizierung),401408(Mittlere
>>> Verbindlichkeitsstufe)
> 
>> I'm unable to reproduce the issue, but I'm a little unsure I have the
>> complete list of steps to do so.  Let's start with these questions:
> 
>> Is your system part of a Windows domain?
> 
>> How exactly are you starting cygserver?
> 
>> When you say "each new session" do you mean opening a new Cygwin Terminal
>> that presents the usual bash+mintty user CLI?  Or is it some other method?
> 
> I think I've observed a related issue.
> I have /tmp set up as user mount, and from time to time, when I log in, it
> points to %WinDir%\TEMP rather than to the current user's %TEMP%, in turn
> making many tools dysfunctional.
> 
> I have to restart cygserver for it to work.

That's interesting.  Do you also have cygserver set up to start on 
Windows boot?  And could you please paste your mount /tmp command so I 
can set that up identically?
Thanks!

..mark

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple