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Date: Tue, 13 May 2025 18:32:29 +0200
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Subject: Re: Using Cygwin installation on network share in CI fails
To: cygwin AT cygwin DOT com
From: =?utf-8?q?Aur=C3=A9lien_Couderc_via_Cygwin?= <cygwin AT cygwin DOT com>
Reply-To: =?UTF-8?Q?Aur=C3=A9lien_Couderc?= <aurelien DOT couderc2002 AT gmail DOT com>
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On Tue, May 13, 2025 at 5:41 PM Brian Inglis via Cygwin
<cygwin AT cygwin DOT com> wrote:
>
> On 2025-05-13 02:33, Aurélien Couderc via Cygwin wrote:
> > On Mon, May 12, 2025 at 7:43 PM Brian Inglis via Cygwin wrote:
> >> On 2025-05-12 10:34, Aurélien Couderc via Cygwin wrote:
> >>> Using Cygwin install on network share in CI fails.
> >>> This seems to be a recent regression, as this was working a year before.
>
> If you have not run it in a year, it is possibly many things have changed in
> your environment.

The CI runs for *every* commit, with hundreds of commits a day.

My... crime... was to update Cygwin to Cygwin 3.6.1. After that,
Cygwin no longer works on WIndows network shares.

> >>> Now on Windows 10 with Cygwin 3.6.1 it fails with error 127.
> >> That can mean a missing DLL function entry.
>
> > No, I do not think so, as Cygwin works fine if I install it on NTFS.
>
> So you are not installing it on NTFS?
> What kind of share are you installing it on?

Windows 10 Enterprise (NT-10.0-19045), we use net use N: ... to mount
the standard Windows network share. AFAIK this is Server Message Block
3.1.

>
> Are you installing it using the *latest* download of Cygwin Setup from
>
>         https://cygwin/com/setup_x86_64.exe

Yes, indeed, we did.

>
> Do the installed files have all their read and exec bits set - this was an issue
> with a recent older release of Cygwin Setup where some files did not.

Yes, all DLL files have, per icacls, at least RX (read, execute) set.

> > WIndows DLLS should be fine, and the system is up to date with patches
> > and has a support contract.
>
> Should be is not definite!
> Patches have been known to cause issues!
> Does the support contract cover supporting the execution of Cygwin and utilities?

I can ask Microsoft support, but seriously for Microsoft "Cygwin" is a
3rd-party product.

>
> > But Cygwin fails if I install it on a Windows network share. Same
> > installation procedure (.\setup-x86_64.exe -q --no-write-registry
> > --no-admin --root %cd%
> > --no-desktop --site "https://mirrors.kernel.org/sourceware/cygwin"),
> > just different drive (N: instead of C:)
>
> A verbal description of a common failure is inadequate.
> We are not mind readers and have no idea how your CI environment is set up.
> Everything works fine in our CI environment, so your environment is defective,
> and we have no information allowing us to do more than speculate and suggest
> what may be an issue.
>
> It appears possible it is an issue with how the share you are using as a network
> drive is now set up.
> It may have been changed recently due to some process or policy change by your
> IT department.
> Please ask them what they have done recently that might affect the share you
> have been using successfully since 2016.
>
> Also please note that recent Windows changes have started blocking Cygwin
> programs with the same names as programs provided by MS (as outdated and
> insecure versions) like bash, curl, ssh*, tar, etc. possibly under the Windows
> security heading of Tamper Protection?

I turned off WIndows Defender, for testing purposes, and the result is the same.

> You have failed to respond to requests for actual information about or from the
> failing environment.
> We need to see actual output from commands of the file system properties and
> directory contents and permissions.

There *IS* no output. Everything which depends on cygwin1.dll just
fails without output.

> Maybe follow the problem reporting guidelines to run cygcheck -hrsv in the CI
> and include the output as a plain text attachment to your post.

I need to anonymise that, or IT will want my reprimation.

But the steps I posted fail on ANY Windows 10 and Windows 11 machine I
have tested so far, Windows Home, Enterprise and Pro.
All you need are the steps I posted, the KEY being doing an
installation on Windows Server Message Block filesystem. That is all.

Aurélien

P.S: I hereby propose a cygcheck -A (anonymise) option, which should
replace hostname, IP addresses and other sensitive data with one way
hashes like MD4 or MD5
-- 
Aurélien Couderc <aurelien DOT couderc2002 AT gmail DOT com>
Big Data/Data mining expert, chess enthusiast

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