bug#35484: GDM failing to start stumpwm after merge

bug#35484: GDM failing to start stumpwm after merge

[Brett Gilio]

Hey all

I just reconfigured my system configuration after the big staging merge
to master. I use StumpWM.

GDM seems to be starting just fine, but after this reconfiguration
stumpwm or X or something is crashing for me and looping me back to GDM.

Where are the logs I can view for this? I see some message appear but
quickly disappear before looping back into GDM.

If I can get the logs I can share them or try and figure it out myself.

Best,
Brett Gilio

bug#35484: GDM failing to start stumpwm after merge

[pelzflorian (Florian Pelz)]

On Sun, Apr 28, 2019 at 11:30:05PM -0500, Brett Gilio wrote:
> Hey all
> 
> I just reconfigured my system configuration after the big staging merge
> to master. I use StumpWM.
> 
> GDM seems to be starting just fine, but after this reconfiguration
> stumpwm or X or something is crashing for me and looping me back to GDM.
> 
> Where are the logs I can view for this? I see some message appear but
> quickly disappear before looping back into GDM.
> 
> If I can get the logs I can share them or try and figure it out myself.
> 
> Best,
> Brett Gilio
> 
> 
> 

I remember having a Gjs out of memory error in
/var/log/gdm/greeter.log before when logging in to GNOME.  Yours is
not an out of memory, is it?

bug#35484: GDM failing to start stumpwm after merge

[Timothy Sample]

Hi Brett,

Brett Gilio <brettg@posteo.net> writes:

> Hey all
>
> I just reconfigured my system configuration after the big staging merge
> to master. I use StumpWM.
>
> GDM seems to be starting just fine, but after this reconfiguration
> stumpwm or X or something is crashing for me and looping me back to GDM.
>
> Where are the logs I can view for this? I see some message appear but
> quickly disappear before looping back into GDM.

GDM logs things to “/var/log/messages”.  However, it may not be useful
in this case (do take a look, though).

> If I can get the logs I can share them or try and figure it out myself.

You could also share some other details about your config.  For
instance, how is StumpWM started?  Do you have a “~/.xsession” script or
does StumpWM provide a “.desktop” file that GDM needs to find?


-- Tim

bug#35484: GDM failing to start stumpwm after merge

[Ricardo Wurmus]

Hey Brett,

> GDM seems to be starting just fine, but after this reconfiguration
> stumpwm or X or something is crashing for me and looping me back to GDM.
>
> Where are the logs I can view for this? I see some message appear but
> quickly disappear before looping back into GDM.

The gdm user’s home directory is /var/lib/gdm/; you may find some log
files there.

--
Ricardo

bug#35484: GDM failing to start stumpwm after merge

[Timothy Sample]

Hi again,

Timothy Sample <samplet@ngyro.com> writes:

> Hi Brett,
>
> Brett Gilio <brettg@posteo.net> writes:
>
>> Hey all
>>
>> I just reconfigured my system configuration after the big staging merge
>> to master. I use StumpWM.
>>
>> GDM seems to be starting just fine, but after this reconfiguration
>> stumpwm or X or something is crashing for me and looping me back to GDM.
>>
>> Where are the logs I can view for this? I see some message appear but
>> quickly disappear before looping back into GDM.
>
> GDM logs things to “/var/log/messages”.  However, it may not be useful
> in this case (do take a look, though).
>
>> If I can get the logs I can share them or try and figure it out myself.
>
> You could also share some other details about your config.  For
> instance, how is StumpWM started?  Do you have a “~/.xsession” script or
> does StumpWM provide a “.desktop” file that GDM needs to find?

After doing some testing in a VM, it looks like this is an issue with my
recent commit: 8caa458953eeac783c73a0e5aaa72842fe3914c9.

I added a placeholder desktop entry file, and even though I did my best
to make it invisible, GDM is still selecting it.  (I tested GNOME and
XFCE, but I guess they were preferred by GDM over the placeholder,
whereas StumpWM is not.  Maybe the has to do with how the names are
sorted.)  I will try and fix this today, but in the mean time, you can
either:

    • go back to using SLiM for now;
    • launch StumpWM from “~/.xsession”; or
    • install another WM, so that you can select StumpWM explicitly when
      logging in (using the little gear icon that shows up when you have
      multiple sessions available).

Sorry!


-- Tim

bug#35484: GDM failing to start stumpwm after merge

[brettg]

On 29.04.2019 18:05, Timothy Sample wrote:
> Hi again,
> 
> Timothy Sample <samplet@ngyro.com> writes:
> 
>> Hi Brett,
>> 
>> Brett Gilio <brettg@posteo.net> writes:
>> 
>>> Hey all
>>> 
>>> I just reconfigured my system configuration after the big staging 
>>> merge
>>> to master. I use StumpWM.
>>> 
>>> GDM seems to be starting just fine, but after this reconfiguration
>>> stumpwm or X or something is crashing for me and looping me back to 
>>> GDM.
>>> 
>>> Where are the logs I can view for this? I see some message appear but
>>> quickly disappear before looping back into GDM.
>> 
>> GDM logs things to “/var/log/messages”.  However, it may not be useful
>> in this case (do take a look, though).
>> 
>>> If I can get the logs I can share them or try and figure it out 
>>> myself.
>> 
>> You could also share some other details about your config.  For
>> instance, how is StumpWM started?  Do you have a “~/.xsession” script 
>> or
>> does StumpWM provide a “.desktop” file that GDM needs to find?
> 
> After doing some testing in a VM, it looks like this is an issue with 
> my
> recent commit: 8caa458953eeac783c73a0e5aaa72842fe3914c9.
> 
> I added a placeholder desktop entry file, and even though I did my best
> to make it invisible, GDM is still selecting it.  (I tested GNOME and
> XFCE, but I guess they were preferred by GDM over the placeholder,
> whereas StumpWM is not.  Maybe the has to do with how the names are
> sorted.)  I will try and fix this today, but in the mean time, you can
> either:
> 
>     • go back to using SLiM for now;
>     • launch StumpWM from “~/.xsession”; or
>     • install another WM, so that you can select StumpWM explicitly 
> when
>       logging in (using the little gear icon that shows up when you 
> have
>       multiple sessions available).
> 
> Sorry!
> 
> 
> -- Tim

Thank you for looking into this Tim! I have gone back to SLiM for the 
time being until it is fixed :).

If anybody else is having this issue, going back to SLiM is really easy, 
check out my commit for reference.

https://github.com/brettgilio/guix-system/commit/64d389db13c2f78ee5c58af28c1639b098113c93

bug#35484: GDM failing to start stumpwm after merge

[Timothy Sample]

[-- Attachment #1: Type: text/plain, Size: 1507 bytes --]

Hi Brett,

brettg@posteo.net writes:

> On 29.04.2019 18:05, Timothy Sample wrote:
>>
>> After doing some testing in a VM, it looks like this is an issue
>> with my
>> recent commit: 8caa458953eeac783c73a0e5aaa72842fe3914c9.
>>
>> I added a placeholder desktop entry file, and even though I did my best
>> to make it invisible, GDM is still selecting it.  (I tested GNOME and
>> XFCE, but I guess they were preferred by GDM over the placeholder,
>> whereas StumpWM is not.  Maybe the has to do with how the names are
>> sorted.)

This is exactly the problem.  To find a default session, it sorts the
names of all the “.desktop” files it can find (using “g_strcmp0”), and
picks the first.  Since we have “GNOME” < “XFCE” < “Fail” < “stumpwm”,
my tests did not catch this error.

I can think of two options for a fix before 1.0 (which is supposed to be
tomorrow!).  The cute one is to just rename “Fail” to “~Fail”, on the
expectation that this will come after most other names when sorted.  The
ugly one is to patch GDM to exclude the placeholder file when looking
for “.desktop” files, and then to select it instead of raising an error
when it can’t find anything.

My preference is for the ugly one, because the cute one feels like
putting a silly hack on top of silly hack – it’s just a bit too much.
I’ve attached a patch.  Thoughts?  (If I don’t hear anything, I will
push it – it’s important that this works for 1.0).


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-gnu-gdm-Avoid-selecting-the-placeholder-session.patch --]
[-- Type: text/x-patch, Size: 2162 bytes --]

From 6b78b1d9c9a4c5ecb55dcd973248310fbbea3a33 Mon Sep 17 00:00:00 2001
From: Timothy Sample <samplet@ngyro.com>
Date: Mon, 29 Apr 2019 14:49:42 -0400
Subject: [PATCH] gnu: gdm: Avoid selecting the placeholder session.

This fixes <https://bugs.gnu.org/35484>.

* gnu/packages/gnome.scm (gdm)[arguments]: Modify the pre-configure phase to
patch GDM to only select the placeholder session if there are no others.
---
 gnu/packages/gnome.scm | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/gnome.scm b/gnu/packages/gnome.scm
index 17dc2fd102..f19b1836d3 100644
--- a/gnu/packages/gnome.scm
+++ b/gnu/packages/gnome.scm
@@ -5597,7 +5597,7 @@ libxml2.")
        (modify-phases %standard-phases
          (add-before
           'configure 'pre-configure
-          (lambda* (#:key inputs #:allow-other-keys)
+          (lambda* (#:key inputs outputs #:allow-other-keys)
             ;; We don't have <systemd/sd-daemon.h>.
             (substitute* '("common/gdm-log.c"
                            "daemon/gdm-server.c"
@@ -5665,6 +5665,16 @@ libxml2.")
               (("\"gnome-session\"")
                (string-append "\"" (assoc-ref inputs "gnome-session")
                               "/bin/gnome-session\"")))
+            ;; Do not automatically select the placeholder session.
+            (substitute* "daemon/gdm-session.c"
+              (("!g_str_has_suffix [(]base_name, \"\\.desktop\"[)]")
+               (string-append "!g_str_has_suffix (base_name, \".desktop\") || "
+                              "(g_strcmp0(search_dirs[i], \""
+                              (assoc-ref outputs "out") "/share/gdm/BuiltInSessions/"
+                              "\") == 0 && "
+                              "g_strcmp0(base_name, \"fail.desktop\") == 0)"))
+              (("g_error [(]\"GdmSession: no session desktop files installed, aborting\\.\\.\\.\"[)];")
+               "{ self->priv->fallback_session_name = g_strdup(\"fail\"); goto out; }"))
             #t))
          ;; GDM requires that there be at least one desktop entry
          ;; file.  This phase installs a hidden one that simply
-- 
2.21.0


[-- Attachment #3: Type: text/plain, Size: 560 bytes --]


In the future, we should find a way to make GDM errors less
catastrophic, but I doubt we could do that in a day (I certainly
couldn’t)!

> Thank you for looking into this Tim! I have gone back to SLiM for the
> time being until it is fixed :).
>
> If anybody else is having this issue, going back to SLiM is really
> easy, check out my commit for reference.
>
> https://github.com/brettgilio/guix-system/commit/64d389db13c2f78ee5c58af28c1639b098113c93

Thanks for providing this.  Hopefully it helps anybody else having
problems.


-- Tim

bug#35484: GDM failing to start stumpwm after merge

[Ludovic Courtès]

Hi Tim,

Timothy Sample <samplet@ngyro.com> skribis:

> I can think of two options for a fix before 1.0 (which is supposed to be
> tomorrow!).  The cute one is to just rename “Fail” to “~Fail”, on the
> expectation that this will come after most other names when sorted.  The
> ugly one is to patch GDM to exclude the placeholder file when looking
> for “.desktop” files, and then to select it instead of raising an error
> when it can’t find anything.
>
> My preference is for the ugly one, because the cute one feels like
> putting a silly hack on top of silly hack – it’s just a bit too much.
> I’ve attached a patch.  Thoughts?  (If I don’t hear anything, I will
> push it – it’s important that this works for 1.0).

I don’t have an opinion as I didn’t follow this closely.

Could you make sure the fix works with the DEs and WMs that the
installer proposes (see (gnu installer services))?

If it does, could you push it also to the ‘version-1.0.0’ branch?

Thank you for looking into this!

Ludo’.

bug#35484: GDM failing to start stumpwm after merge

[Brett Gilio]

Timothy Sample writes:

> Hi Brett,
>
> brettg@posteo.net writes:
>
>> On 29.04.2019 18:05, Timothy Sample wrote:
>>>
>>> After doing some testing in a VM, it looks like this is an issue
>>> with my
>>> recent commit: 8caa458953eeac783c73a0e5aaa72842fe3914c9.
>>>
>>> I added a placeholder desktop entry file, and even though I did my best
>>> to make it invisible, GDM is still selecting it.  (I tested GNOME and
>>> XFCE, but I guess they were preferred by GDM over the placeholder,
>>> whereas StumpWM is not.  Maybe the has to do with how the names are
>>> sorted.)
>
> This is exactly the problem.  To find a default session, it sorts the
> names of all the “.desktop” files it can find (using “g_strcmp0”), and
> picks the first.  Since we have “GNOME” < “XFCE” < “Fail” < “stumpwm”,
> my tests did not catch this error.
>
> I can think of two options for a fix before 1.0 (which is supposed to be
> tomorrow!).  The cute one is to just rename “Fail” to “~Fail”, on the
> expectation that this will come after most other names when sorted.  The
> ugly one is to patch GDM to exclude the placeholder file when looking
> for “.desktop” files, and then to select it instead of raising an error
> when it can’t find anything.
>
> My preference is for the ugly one, because the cute one feels like
> putting a silly hack on top of silly hack – it’s just a bit too much.
> I’ve attached a patch.  Thoughts?  (If I don’t hear anything, I will
> push it – it’s important that this works for 1.0).
>
>
> In the future, we should find a way to make GDM errors less
> catastrophic, but I doubt we could do that in a day (I certainly
> couldn’t)!
>
>> Thank you for looking into this Tim! I have gone back to SLiM for the
>> time being until it is fixed :).
>>
>> If anybody else is having this issue, going back to SLiM is really
>> easy, check out my commit for reference.
>>
>> https://github.com/brettgilio/guix-system/commit/64d389db13c2f78ee5c58af28c1639b098113c93
>
> Thanks for providing this.  Hopefully it helps anybody else having
> problems.
>
>
> -- Tim

I think the uglier version is more generic and less likely to cause
future errors. But, it is a matter of time. The uglier one is likely
going to be more terse.

Do you need any help on my end?

Brett Gilio

bug#35484: GDM failing to start stumpwm after merge

[Timothy Sample]

Hi Ludo,

Ludovic Courtès <ludo@gnu.org> writes:

> Hi Tim,
>
> Timothy Sample <samplet@ngyro.com> skribis:
>
>> I can think of two options for a fix before 1.0 (which is supposed to be
>> tomorrow!).  The cute one is to just rename “Fail” to “~Fail”, on the
>> expectation that this will come after most other names when sorted.  The
>> ugly one is to patch GDM to exclude the placeholder file when looking
>> for “.desktop” files, and then to select it instead of raising an error
>> when it can’t find anything.
>>
>> My preference is for the ugly one, because the cute one feels like
>> putting a silly hack on top of silly hack – it’s just a bit too much.
>> I’ve attached a patch.  Thoughts?  (If I don’t hear anything, I will
>> push it – it’s important that this works for 1.0).
>
> I don’t have an opinion as I didn’t follow this closely.

Okay.  I picked the more robust solution, but I still hope it doesn’t
stick around too long.  :)

> Could you make sure the fix works with the DEs and WMs that the
> installer proposes (see (gnu installer services))?

I tested all of the DEs listed there except for MATE, which I could not
compile.  I had to patch i3 and awesome to use absolute paths in their
“.desktop” files.  (The “xinitrc” script can find the binaries in $PATH,
but GDM cannot find the “TryExec” binaries unless they are absolute.
This is no doubt related to the other $PATH issues we saw with GDM.)

> If it does, could you push it also to the ‘version-1.0.0’ branch?

I pushed three commits to master:

    1. e8c6e771c1 gnu: gdm: Avoid selecting the placeholder session.
    2. 4ec42524dd gnu: awesome: Use absolute paths in session file.
    3. aa7cdc57dc gnu: i3-wm: Use absolute paths in session files.

I then cherry-picked them onto the “version-1.0.0” branch.  Sorry if
that’s not what you meant.

> Thank you for looking into this!

No problem.  Thanks for the quick response!


-- Tim

bug#35484: GDM failing to start stumpwm after merge

[Timothy Sample]

Hi Brett,

Brett Gilio <brettg@posteo.net> writes:

> Timothy Sample writes:
>
>> Hi Brett,
>>
>> [...]
>>
>> I can think of two options for a fix before 1.0 (which is supposed to be
>> tomorrow!).  The cute one is to just rename “Fail” to “~Fail”, on the
>> expectation that this will come after most other names when sorted.  The
>> ugly one is to patch GDM to exclude the placeholder file when looking
>> for “.desktop” files, and then to select it instead of raising an error
>> when it can’t find anything.
>>
>> My preference is for the ugly one, because the cute one feels like
>> putting a silly hack on top of silly hack – it’s just a bit too much.
>> I’ve attached a patch.  Thoughts?  (If I don’t hear anything, I will
>> push it – it’s important that this works for 1.0).
>>
>>
>> In the future, we should find a way to make GDM errors less
>> catastrophic, but I doubt we could do that in a day (I certainly
>> couldn’t)!
>>
>>> Thank you for looking into this Tim! I have gone back to SLiM for the
>>> time being until it is fixed :).
>>>
>>> If anybody else is having this issue, going back to SLiM is really
>>> easy, check out my commit for reference.
>>>
>>> https://github.com/brettgilio/guix-system/commit/64d389db13c2f78ee5c58af28c1639b098113c93
>>
>> Thanks for providing this.  Hopefully it helps anybody else having
>> problems.
>>
>>
>> -- Tim
>
> I think the uglier version is more generic and less likely to cause
> future errors. But, it is a matter of time. The uglier one is likely
> going to be more terse.
>
> Do you need any help on my end?

No, but thank you for offering and thanks for catching my mistake before
we released 1.0.  :)

I pushed e8c6e771c199c02b748eb66d3a03c46d2a32ca29 to master, which
should fix this.  Hence, I’m closing the bug.


-- Tim

bug#35484: GDM failing to start stumpwm after merge

[Ludovic Courtès]

Hello!

Timothy Sample <samplet@ngyro.com> skribis:

> I pushed three commits to master:
>
>     1. e8c6e771c1 gnu: gdm: Avoid selecting the placeholder session.
>     2. 4ec42524dd gnu: awesome: Use absolute paths in session file.
>     3. aa7cdc57dc gnu: i3-wm: Use absolute paths in session files.
>
> I then cherry-picked them onto the “version-1.0.0” branch.  Sorry if
> that’s not what you meant.

That’s exactly what I meant, thank you!  :-)

Ludo’.