Printer configuration

Printer configuration

[Kyle Andrews]

Dear Guix,

Could you help me get my printer working?

I setup my cups service:

...
(use-modules ...
	     (gnu packages cups)
             ...)
(use-service-modules ... cups ...)
...
  (service cups-service-type
		   (cups-configuration
		    (extensions
		     (list hplip-minimal cups-filters splix))
		    (server-name host-name)
		    (host-name-lookups #t)
		    (web-interface? #t)))
...

Then I reconfigured my system and restarted. Now I can access the CUPS
page on localhost:631. However, I could not figure out that interface
for the life of me. Instead, I found out I could install the
`system-config-printer' package which provided a setup utility that
actually made sense, giving me hope of falling into a "pit of
success". It detected my printer, great! Unfortunately, it failed to
print a test page, popping up a warning box with the text:

Printer 'SCX-4200' requires the '/gnu/store/.../cups/filter/rastertoqpdl'
program but it is not currently installed.

I'm not sure what to do now. Thanks in advance for any suggestions on
how to resolve this.

Best Regards,
Kyle

Re: Printer configuration

[Kyle Andrews]

Kyle Andrews writes:

> Dear Guix,
>
> Could you help me get my printer working?
>
> I setup my cups service:
>
> ...
> (use-modules ...
> 	     (gnu packages cups)
>              ...)
> (use-service-modules ... cups ...)
> ...
>   (service cups-service-type
> 		   (cups-configuration
> 		    (extensions
> 		     (list hplip-minimal cups-filters splix))
> 		    (server-name host-name)
> 		    (host-name-lookups #t)
> 		    (web-interface? #t)))
> ...
>
> Then I reconfigured my system and restarted. Now I can access the CUPS
> page on localhost:631. However, I could not figure out that interface
> for the life of me. Instead, I found out I could install the
> `system-config-printer' package which provided a setup utility that
> actually made sense, giving me hope of falling into a "pit of
> success". It detected my printer, great! Unfortunately, it failed to
> print a test page, popping up a warning box with the text:
>
> Printer 'SCX-4200' requires the '/gnu/store/.../cups/filter/rastertoqpdl'
> program but it is not currently installed.
>
> I'm not sure what to do now. Thanks in advance for any suggestions on
> how to resolve this.
>
> Best Regards,
> Kyle

After sending I realized there were two pieces of information I forgot
to include that might be of interest towards diagnosing the difficulty:

1.) The printer is a SCX-4200 and is listed as working on
openprinting.org.

2.) the slice of the error message I showed was incomplete: the guix
package where rastertoqpdl is being searched for is in cups, yet the
tool is clearly available in the splix package. Why is
system-config-printer looking in the wrong package? How can I make the
service see both?

Thanks,
Kyle

Re: Printer configuration

[Wiktor Żelazny]

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On Thu, Jun 25, 2020 at 10:11:36PM -0400, Kyle Andrews wrote:

> (use-modules ...
> 	     (gnu packages cups)
>              ...)

>   (service cups-service-type
> 		   (cups-configuration
> 		    (extensions
> 		     (list hplip-minimal cups-filters splix))
> 		    (server-name host-name)
> 		    (host-name-lookups #t)
> 		    (web-interface? #t)))

Hi Kyle,

Just a wild guess, but how about declaring cups and splix in the
`packages` part of your config.scm?

WŻ

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Re: Printer configuration

[Kyle Andrews]

Wiktor Żelazny writes:

> On Thu, Jun 25, 2020 at 10:11:36PM -0400, Kyle Andrews wrote:
>
>> (use-modules ...
>> 	     (gnu packages cups)
>>              ...)
>
>>   (service cups-service-type
>> 		   (cups-configuration
>> 		    (extensions
>> 		     (list hplip-minimal cups-filters splix))
>> 		    (server-name host-name)
>> 		    (host-name-lookups #t)
>> 		    (web-interface? #t)))
>
> Hi Kyle,
>
> Just a wild guess, but how about declaring cups and splix in the
> `packages` part of your config.scm?
>
> WŻ

Thanks for the suggestion, WZ! I gave it a shot adding cups and splix
into my default packages. Unfortunately, even after completely
restarting the computer I observed no change in the error I get when
trying to print a test page.

Re: Printer configuration

[Wiktor Żelazny]

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On Fri, Jun 26, 2020 at 12:56:08PM -0400, Kyle Andrews wrote:

> I observed no change in the error I get when trying to print a test
> page.

Does /gnu/store/.../cups/filter/rastertoqpdl exist?

Is the user printing the test page a member of the lp group (lpadmin
might also help)?

WŻ

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Re: Printer configuration

[Kyle Andrews]

Wiktor Żelazny writes:

> On Fri, Jun 26, 2020 at 12:56:08PM -0400, Kyle Andrews wrote:
>
>> I observed no change in the error I get when trying to print a test
>> page.
>
> Does /gnu/store/.../cups/filter/rastertoqpdl exist?
>
> Is the user printing the test page a member of the lp group (lpadmin
> might also help)?
>
> WŻ

Hi WZ,

Thanks for following up.

> Does /gnu/store/.../cups/filter/rastertoqpdl exist?

Yes, it exists in the splix package, but not in the cups
package. Looking at the Guix source code I saw that
~system-config-printer~ (in ~guix/gnu/packages/gnome.scm~) takes input
from cups on build, but not from splix or other print drivers. Could
that be part of the problem?

> Is the user printing the test page a member of the lp group (lpadmin
> might also help)?

The user is in the lp group. I didn't know about lpadmin. I will add
that group as well and see if it changes anything. The CUPS localhost
page was behaving strangely (stalling on load) when I tried to click the
administration tab. Thanks for the tip!

Kyle

Re: Printer configuration

[Wiktor Żelazny]

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On Fri, Jun 26, 2020 at 02:13:14PM -0400, Kyle Andrews wrote:
>
> Wiktor Żelazny writes:
>
> > Does /gnu/store/.../cups/filter/rastertoqpdl exist?
>
> Yes, it exists in the splix package, but not in the cups package.
> Looking at the Guix source code I saw that ~system-config-printer~ (in
> ~guix/gnu/packages/gnome.scm~) takes input from cups on build, but not
> from splix or other print drivers. Could that be part of the problem?

I wouldn’t be surprised. On the other hand, it does not import other
extensions, such as hplip and foomatic-filters, either.

Did you run guix system reconfigure after adding the packages to
config.scm? Did you try removing and adding the printer again
afterwards?

Does a /var/guix/profiles/system/profile/lib/cups/filter/rastertoqpdl
symlink exist in your filesystem? I think you could try changing the
rastertoqpdl path defined in the system-config-printer configuration (or
CUPS configuration, assuming it’s just a CUPS GUI frontend) from
/gnu/store/… to that path. /gnu/store/ contents are volatile. Again,
just guessing; perhaps the path is hardcoded into the CUPS/splix build
and uneditable.

WŻ

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Re: Printer configuration

[Kyle Andrews]

Wiktor Żelazny writes:

> On Fri, Jun 26, 2020 at 02:13:14PM -0400, Kyle Andrews wrote:
>>
>> Wiktor Żelazny writes:
>>
>> > Does /gnu/store/.../cups/filter/rastertoqpdl exist?
>>
>> Yes, it exists in the splix package, but not in the cups package.
>> Looking at the Guix source code I saw that ~system-config-printer~ (in
>> ~guix/gnu/packages/gnome.scm~) takes input from cups on build, but not
>> from splix or other print drivers. Could that be part of the problem?
>
> I wouldn’t be surprised. On the other hand, it does not import other
> extensions, such as hplip and foomatic-filters, either.
>
> Did you run guix system reconfigure after adding the packages to
> config.scm? Did you try removing and adding the printer again
> afterwards?
>
> Does a /var/guix/profiles/system/profile/lib/cups/filter/rastertoqpdl
> symlink exist in your filesystem? I think you could try changing the
> rastertoqpdl path defined in the system-config-printer configuration (or
> CUPS configuration, assuming it’s just a CUPS GUI frontend) from
> /gnu/store/… to that path. /gnu/store/ contents are volatile. Again,
> just guessing; perhaps the path is hardcoded into the CUPS/splix build
> and uneditable.
>
> WŻ

Hi WZ,

> Did you run guix system reconfigure after adding the packages to
> config.scm? Did you try removing and adding the printer again
> afterwards?

I did reconfigure, but I didn't try removing and adding the printer
again.

> Does a /var/guix/profiles/system/profile/lib/cups/filter/rastertoqpdl
> symlink exist in your filesystem? I think you could try changing the
> rastertoqpdl path defined in the system-config-printer configuration (or
> CUPS configuration, assuming it’s just a CUPS GUI frontend) from
> /gnu/store/… to that path. /gnu/store/ contents are volatile. Again,
> just guessing; perhaps the path is hardcoded into the CUPS/splix build
> and uneditable.

It does appear to exist. Actually, I figured out how to successfully
print a document using ~libreoffice --headless -p test.odt~. So, I think
my printer problem is actually reflecting a problem with
system-config-printer.

Kyle

Re: Printer configuration

[Wiktor Żelazny]

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On Fri, Jun 26, 2020 at 06:12:23PM -0400, Kyle Andrews wrote:

> I figured out how to successfully print a document using ~libreoffice
> --headless -p test.odt~. So, I think my printer problem is actually
> reflecting a problem with system-config-printer.

Or perhaps the difference is that that print job did not have to involve
rastertoqpdl. Have you tried something like

   lpr a-simple-text-file.txt

?

Of course, I second Tobias in advising you to try localhost:631. CUPS
may figure out some smart configuration for you.

Good luck,

WŻ

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Re: Printer configuration

[Kyle Andrews]

Wiktor Żelazny writes:

> On Fri, Jun 26, 2020 at 06:12:23PM -0400, Kyle Andrews wrote:
>
>> I figured out how to successfully print a document using ~libreoffice
>> --headless -p test.odt~. So, I think my printer problem is actually
>> reflecting a problem with system-config-printer.
>
> Or perhaps the difference is that that print job did not have to involve
> rastertoqpdl. Have you tried something like
>
>    lpr a-simple-text-file.txt
>
> ?
>

Yes, I did. That worked too!

> Of course, I second Tobias in advising you to try localhost:631. CUPS
> may figure out some smart configuration for you.

I was able to print a test page through the CUPS web interface as
well. So, this further points to system-config-printer being buggy.

> Good luck,
>
> WŻ

Thanks for all your help.

Kyle

Re: Printer configuration

[Tobias Geerinckx-Rice]

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Kyle,

I'd strongly recommend using the ‘real’ CUPS interface at 
localhost:631 over any third-party helper, but…

Kyle Andrews 写道：
> The CUPS localhost page was behaving strangely (stalling on 
> load)
> when I tried to click the administration tab.

I can confirm that the Administration tab freezes on my laptop and 
print server (CUPS proxied through nginx).  That's new :-/  I'll 
report a bug for that.

Thanks,

T G-R

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