GNU bug report logs - #76343
shepherd 1.0.2 --help: warning: call to environ while multiple threads are running; further behavior unspecified.

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Simon Josefsson <simon <at> josefsson.org>
To: bug-guix <at> gnu.org
Subject: shepherd 1.0.2 --help: warning: call to environ while multiple
 threads are running; further behavior unspecified.
Date: Sun, 16 Feb 2025 18:30:31 +0100

[Message part 1 (text/plain, inline)]

Hi

It seems shepherd in Debian print the following on a simple --help:

132s warning: call to environ while multiple threads are running;
132s          further behavior unspecified.

I can't find the error message in guile-fibers or shepherd source code.
Any ideas where it comes from and how to fix it?

Version 1.0.0:
https://ci.debian.net/packages/s/shepherd/testing/amd64/57880388/

Version 1.0.2:
https://salsa.debian.org/debian/shepherd/-/jobs/7101207#L718

/Simon

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Message #8 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Tomas Volf <~@wolfsden.cz>
To: Simon Josefsson via Bug reports for GNU Guix <bug-guix <at> gnu.org>
Cc: Simon Josefsson <simon <at> josefsson.org>, 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Sun, 16 Feb 2025 22:43:13 +0100

[Message part 1 (text/plain, inline)]

Simon Josefsson via Bug reports for GNU Guix <bug-guix <at> gnu.org> writes:

> Hi
>
> It seems shepherd in Debian print the following on a simple --help:
>
> 132s warning: call to environ while multiple threads are running;
> 132s          further behavior unspecified.
>
> I can't find the error message in guile-fibers or shepherd source code.
> Any ideas where it comes from

Guile itself, libguile/posix.c.

--8<---------------cut here---------------start------------->8---
libguile/posix.c
1724-  if (scm_ilength (scm_all_threads ()) != 1)
1725-    scm_display
1726-      (scm_from_latin1_string
1727:       ("warning: call to environ while multiple threads are running;\n"
1728-        "         further behavior unspecified.\n"),
1729-       scm_current_warning_port ());
1730-
--8<---------------cut here---------------end--------------->8---

> and how to fix it?

Do not call (environ) when multiple threads are running, but I assume
that is not actually helpful advice. :)

>
> Version 1.0.0:
> https://ci.debian.net/packages/s/shepherd/testing/amd64/57880388/
>
> Version 1.0.2:
> https://salsa.debian.org/debian/shepherd/-/jobs/7101207#L718
>
> /Simon
>

-- 
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.

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Message #14 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Simon Josefsson <simon <at> josefsson.org>
To: Tomas Volf <~@wolfsden.cz>
Cc: 76343 <at> debbugs.gnu.org,
 Simon Josefsson via Bug reports for GNU Guix <bug-guix <at> gnu.org>
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Mon, 17 Feb 2025 00:33:14 +0100

[Message part 1 (text/plain, inline)]

Tomas Volf <~@wolfsden.cz> writes:

> Simon Josefsson via Bug reports for GNU Guix <bug-guix <at> gnu.org> writes:
>
>> Hi
>>
>> It seems shepherd in Debian print the following on a simple --help:
>>
>> 132s warning: call to environ while multiple threads are running;
>> 132s          further behavior unspecified.
>>
>> I can't find the error message in guile-fibers or shepherd source code.
>> Any ideas where it comes from
>
> Guile itself, libguile/posix.c.
>
> libguile/posix.c
> 1724-  if (scm_ilength (scm_all_threads ()) != 1)
> 1725-    scm_display
> 1726-      (scm_from_latin1_string
> 1727:       ("warning: call to environ while multiple threads are running;\n"
> 1728-        "         further behavior unspecified.\n"),
> 1729-       scm_current_warning_port ());
> 1730-
>
>> and how to fix it?
>
> Do not call (environ) when multiple threads are running, but I assume
> that is not actually helpful advice. :)

Thank you for the pointer.  Interesting - why isn't this triggered on
Guix but only when building shepherd on a foreign distribution like
Debian?

Is the message really correct?  I thought guile-fibers and shepherd did
not use threads at all.

If it is possible to make --help and --version avoid launching new
threads, that would be nice to resolve this warning for at least the
simple use-case of doing --help and --version.

/Simon

>>
>> Version 1.0.0:
>> https://ci.debian.net/packages/s/shepherd/testing/amd64/57880388/
>>
>> Version 1.0.2:
>> https://salsa.debian.org/debian/shepherd/-/jobs/7101207#L718
>>
>> /Simon
>>

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Message #20 received at 76343 <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: Simon Josefsson <simon <at> josefsson.org>
Cc: 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Wed, 26 Feb 2025 16:50:59 +0100

Hi,

Simon Josefsson <simon <at> josefsson.org> skribis:

> It seems shepherd in Debian print the following on a simple --help:
>
> 132s warning: call to environ while multiple threads are running;
> 132s          further behavior unspecified.

This is a bug introduced in Guile 3.0.10 (Guix still uses 3.0.9), for
which I’ve now sent a patch:

  https://issues.guix.gnu.org/76589

Olivier Dion submitted another patch, which complements the one above:

  https://lists.gnu.org/archive/html/guile-devel/2025-02/msg00036.html

Thanks,
Ludo’.

Message #23 received at 76343 <at> debbugs.gnu.org (full text, mbox):

From: Simon Josefsson <simon <at> josefsson.org>
To: Ludovic Courtès <ludo <at> gnu.org>
Cc: 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ while
 multiple threads are running; further behavior unspecified.
Date: Wed, 26 Feb 2025 17:06:58 +0100

Thank you! Does this make shepherd Debian packages useless, or can we suggest people to ignore the warning? Any simple way to patch it out from within shepherd? The Debian freeze is in two weeks and it would be nice to give a good first impression to people try it shepherd from Debian… i could try to get guile patched, but it is getting late.

/Simon

> 26 feb. 2025 kl. 16:51 skrev Ludovic Courtès <ludo <at> gnu.org>:
> 
> Hi,
> 
> Simon Josefsson <simon <at> josefsson.org> skribis:
> 
>> It seems shepherd in Debian print the following on a simple --help:
>> 
>> 132s warning: call to environ while multiple threads are running;
>> 132s          further behavior unspecified.
> 
> This is a bug introduced in Guile 3.0.10 (Guix still uses 3.0.9), for
> which I’ve now sent a patch:
> 
>  https://issues.guix.gnu.org/76589
> 
> Olivier Dion submitted another patch, which complements the one above:
> 
>  https://lists.gnu.org/archive/html/guile-devel/2025-02/msg00036.html
> 
> Thanks,
> Ludo’.

Message #26 received at 76343 <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: Simon Josefsson <simon <at> josefsson.org>
Cc: 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Thu, 27 Feb 2025 17:26:57 +0100

Hi Simon,

Simon Josefsson <simon <at> josefsson.org> skribis:

> Thank you! Does this make shepherd Debian packages useless, or can we suggest people to ignore the warning? Any simple way to patch it out from within shepherd? The Debian freeze is in two weeks and it would be nice to give a good first impression to people try it shepherd from Debian… i could try to get guile patched, but it is getting late.

A simple way would be to patch out the ‘environ’ warning in Guile: it
didn’t exist before 3.0.10, it’s bogus (it fires even when you’re not
mutating the environment and even with just a single user thread, as is
the case here), and the comment itself doesn’t change program behavior.

If that’s not adequate, we could try and come up with a quick hack for
shepherd to avoid the ‘environ’ call at the top-level (though that’s
probably not something I would consider for inclusion in the Shepherd
proper.)

WDYT?

Ludo’.

Message #29 received at 76343 <at> debbugs.gnu.org (full text, mbox):

From: Simon Josefsson <simon <at> josefsson.org>
To: Ludovic Courtès <ludo <at> gnu.org>
Cc: 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Tue, 04 Mar 2025 15:06:45 +0100

[Message part 1 (text/plain, inline)]

tor 2025-02-27 klockan 17:26 +0100 skrev Ludovic Courtès:
> Hi Simon,
> 
> Simon Josefsson <simon <at> josefsson.org> skribis:
> 
> > Thank you! Does this make shepherd Debian packages useless, or can
> > we suggest people to ignore the warning? Any simple way to patch it
> > out from within shepherd? The Debian freeze is in two weeks and it
> > would be nice to give a good first impression to people try it
> > shepherd from Debian… i could try to get guile patched, but it is
> > getting late.
> 
> A simple way would be to patch out the ‘environ’ warning in Guile: it
> didn’t exist before 3.0.10, it’s bogus (it fires even when you’re not
> mutating the environment and even with just a single user thread, as
> is
> the case here), and the comment itself doesn’t change program
> behavior.
> 
> If that’s not adequate, we could try and come up with a quick hack
> for
> shepherd to avoid the ‘environ’ call at the top-level (though that’s
> probably not something I would consider for inclusion in the Shepherd
> proper.)

A shephard-specific patch would be the simplest at this point, I think.
 
Do you have some idea how to do that?  I agree it seems like a Debian-
specific patch for now.

OTOH, maybe this is not critical.  It is a stderr warning message.  But
it does look ugly, and may give a bad first impression for Debian
people migrating towards Guix.

/Simon

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Message #32 received at 76343 <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: Simon Josefsson <simon <at> josefsson.org>
Cc: 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Tue, 04 Mar 2025 16:39:46 +0100

[Message part 1 (text/plain, inline)]

Hi,

Simon Josefsson <simon <at> josefsson.org> skribis:

> A shephard-specific patch would be the simplest at this point, I think.
>  
> Do you have some idea how to do that?  I agree it seems like a Debian-
> specific patch for now.

The patch below appears to do the trick.  I guess I could just as well
integrate it in the next 1.0.x bug-release.

Does it work for you?

Thanks,
Ludo’.

[Message part 2 (text/x-patch, inline)]

diff --git a/modules/shepherd.scm b/modules/shepherd.scm
index d55373a..a35a415 100644
--- a/modules/shepherd.scm
+++ b/modules/shepherd.scm
@@ -515,7 +515,11 @@ fork in the child process."
                          ;; stdout.  Redirect stdout to the bitbucket so we
                          ;; don't log twice.
                          (%make-void-port "w")
-                         (current-output-port)))))
+                         (current-output-port))))
+
+                   ;; In Guile 3.0.10, calling 'environ' from the top-level
+                   ;; triggers a warning so do it from here.
+                   (default-environment-variables (environ)))
 
       (parameterize ((current-output-port (%current-service-output-port)))
         (set-port-encoding! (log-output-port) "UTF-8")
diff --git a/modules/shepherd/service.scm b/modules/shepherd/service.scm
index 2d64897..c8667e6 100644
--- a/modules/shepherd/service.scm
+++ b/modules/shepherd/service.scm
@@ -1437,7 +1437,7 @@ background:~{ ~a~}."
 (define default-environment-variables
   ;; The default list of environment variable name/value pairs that should be
   ;; set when starting a service.
-  (make-parameter (environ)))
+  (make-parameter '()))
 
 (define default-pid-file-timeout
   ;; Maximum number of seconds to wait for a PID file to show up.

Message #35 received at 76343 <at> debbugs.gnu.org (full text, mbox):

From: Simon Josefsson <simon <at> josefsson.org>
To: Ludovic Courtès <ludo <at> gnu.org>
Cc: 76343 <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Tue, 04 Mar 2025 17:20:03 +0100

[Message part 1 (text/plain, inline)]

Ludovic Courtès <ludo <at> gnu.org> writes:

> Hi,
>
> Simon Josefsson <simon <at> josefsson.org> skribis:
>
>> A shephard-specific patch would be the simplest at this point, I think.
>>  
>> Do you have some idea how to do that?  I agree it seems like a Debian-
>> specific patch for now.
>
> The patch below appears to do the trick.  I guess I could just as well
> integrate it in the next 1.0.x bug-release.
>
> Does it work for you?

It does, yes!

Breaking: https://salsa.debian.org/debian/shepherd/-/jobs/7197263
Working: https://salsa.debian.org/debian/shepherd/-/jobs/7197290

The only difference is your patch.  I'll upload this eventually.

Thanks,
/Simon

>
> Thanks,
> Ludo’.
>
> diff --git a/modules/shepherd.scm b/modules/shepherd.scm
> index d55373a..a35a415 100644
> --- a/modules/shepherd.scm
> +++ b/modules/shepherd.scm
> @@ -515,7 +515,11 @@ fork in the child process."
>                           ;; stdout.  Redirect stdout to the bitbucket so we
>                           ;; don't log twice.
>                           (%make-void-port "w")
> -                         (current-output-port)))))
> +                         (current-output-port))))
> +
> +                   ;; In Guile 3.0.10, calling 'environ' from the top-level
> +                   ;; triggers a warning so do it from here.
> +                   (default-environment-variables (environ)))
>  
>        (parameterize ((current-output-port (%current-service-output-port)))
>          (set-port-encoding! (log-output-port) "UTF-8")
> diff --git a/modules/shepherd/service.scm b/modules/shepherd/service.scm
> index 2d64897..c8667e6 100644
> --- a/modules/shepherd/service.scm
> +++ b/modules/shepherd/service.scm
> @@ -1437,7 +1437,7 @@ background:~{ ~a~}."
>  (define default-environment-variables
>    ;; The default list of environment variable name/value pairs that should be
>    ;; set when starting a service.
> -  (make-parameter (environ)))
> +  (make-parameter '()))
>  
>  (define default-pid-file-timeout
>    ;; Maximum number of seconds to wait for a PID file to show up.
>

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Message #40 received at 76343-done <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: Simon Josefsson <simon <at> josefsson.org>
Cc: 76343-done <at> debbugs.gnu.org
Subject: Re: bug#76343: shepherd 1.0.2 --help: warning: call to environ
 while multiple threads are running; further behavior unspecified.
Date: Thu, 06 Mar 2025 16:26:29 +0100

Simon Josefsson <simon <at> josefsson.org> skribis:

> Ludovic Courtès <ludo <at> gnu.org> writes:
>
>> Hi,
>>
>> Simon Josefsson <simon <at> josefsson.org> skribis:
>>
>>> A shephard-specific patch would be the simplest at this point, I think.
>>>  
>>> Do you have some idea how to do that?  I agree it seems like a Debian-
>>> specific patch for now.
>>
>> The patch below appears to do the trick.  I guess I could just as well
>> integrate it in the next 1.0.x bug-release.
>>
>> Does it work for you?
>
> It does, yes!

Excellent. :-)

Pushed in the Shepherd as 8e951de13120729907c527d4a420b579aec944f4.

Thanks!

Ludo’.

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