SANE / simple-scan working for anyone?

SANE / simple-scan working for anyone?

[Mark H Weaver]

Has anyone successfully scanned documents with SANE on a Guix System?

I just tried running 'simple-scan' with a CanoScan N1240U/LiDE 30
connected via USB, which has "complete" support according to the SANE
docs.  Although "lsusb" shows the scanner:

  mhw@jojen ~$ lsusb
  Bus 006 Device 002: ID 04a9:220e Canon, Inc. CanoScan N1240U/LiDE 30

'simple-scan' says "No scanners detected".  I took a look at the
'strace' output, and one thing I noticed is that it tries to open
/dev/usb/, which doesn't exist on my system.

Before I spend more time investigating, does anyone else have insight on
this?  Has anyone successfully used USB scanners on Guix systems?

        Mark

Re: SANE / simple-scan working for anyone?

[Tobias Geerinckx-Rice]

Mark,

What a coincidence:

Mark H. Weaver wrote:
> I just tried running 'simple-scan' with a CanoScan N1240U/LiDE 
> 30
> connected via USB, which has "complete" support according to the 
> SANE
> docs.  Although "lsusb" shows the scanner:

I had the exact same problem yesterday with my CanoScan N670U/LiDE 
20, which has also been fully supported by SANE for over a decade. 
Neither Simple Scan nor xsane reported any scanners.  I ended up 
borrowing an Ubuntu machine to do the job…

I left home immediately after and won't be able to test it further 
before the end of the week.

> Has anyone successfully scanned documents with SANE on a Guix 
> System?

Yes, but I hadn't tried recently.

Kind regards,

T G-R

Re: SANE / simple-scan working for anyone?

[Tobias Geerinckx-Rice]

Mark,

Tobias Geerinckx-Rice wrote:
> Mark H. Weaver wrote:
>> I just tried running 'simple-scan' with a CanoScan N1240U/LiDE 
>> 30
>> connected via USB, which has "complete" support according to 
>> the
>> SANE
>> docs.  Although "lsusb" shows the scanner:
>
> I had the exact same problem yesterday with my CanoScan 
> N670U/LiDE 20,
> which has also been fully supported by SANE for over a decade.

(Try 18 years.  Yikes…)

I am able to scan after commit 
abe6e670d356b8333b41c7359c0ab25a58fe736b.

Could you confirm that this works for you, too, and close this 
bug?

Kind regards,

T G-R

Re: SANE / simple-scan working for anyone?

[Tobias Geerinckx-Rice]

Tobias Geerinckx-Rice wrote:
> Could you confirm that this works for you, too, and close this 
> bug?

…in your mind and heart, since this is guix-devel…

Bed time,

T G-R

Re: SANE / simple-scan working for anyone?

[Jack Hill]

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Mark,

Did you end up getting your scanning issue resolved? You may have seem my 
own scanning-related adventures over on help-guix [0] where I discovered 
that adding the udev rules from sane-backends was needed. The service 
definition that I used to add them is:

(simple-service 'sane-udev-rules udev-service-type (list sane-backends))

I found that looking at the output of `scanimage -L` from the 
sane-backends package (yes there are user-facing tools in there ☺) as both 
my user and root helpful.

Best,
Jack

[0] https://lists.gnu.org/archive/html/help-guix/2019-03/msg00071.html

Re: SANE / simple-scan working for anyone?

[Tobias Geerinckx-Rice]

Jack,

Jack Hill wrote:
> Mark,

I'm not Mark, but that's my cross to bear.  I'll answer anyway 
since we share an ancient USB scanner and a reproducible OS.

> Did you end up getting your scanning issue resolved?

Yes and no.  I ended up doing all my scanning with the 
command-line ‘scanimage’ (and adding PNG support to it), and 
cropping with the GIMP where needed.  Not ideal but it works 
reliably.

Simple Scan doesn't.  It recognises my scanner (not a difficult 
job and SANE's to boot), but actually scanning (slowly) produces a 
black page, without moving the scanner head at all.

Sometimes Simple Scan will suddenly work *after* I've scanned 
something with ‘scanimage’ directly.  Other times, it still won't.

XSANE (which isn't on master yet) just freezes as soon as I hit 
the ‘Scan’ button.

Both GUIs worked fine with network scanners.

> You may have seem
> my own scanning-related adventures over on help-guix [0] where I
> discovered that adding the udev rules from sane-backends was
> needed. The service definition that I used to add them is:
>
> (simple-service 'sane-udev-rules udev-service-type (list 
> sane-backends))
>
> I found that looking at the output of `scanimage -L` from the
> sane-backends package (yes there are user-facing tools in there 
> ☺)
> as both my user and root helpful.

Interesting.  Here, being root makes no difference (and I can scan 
without sudo).

Kind regards,

T G-R

Re: SANE / simple-scan working for anyone?

[Tobias Geerinckx-Rice]

From the sane-backends change log:

  “Note 3: The Linux USB3 workaround which was added in version
   1.0.25 is now disabled by default. If you have difficulty using
   a scanner which previously worked, or intermittent scanner
   availability, try setting the new environment variable
   SANE_USB_WORKAROUND=1 before starting your frontend.”

I'll try that when I'm reunited with mine.

Kind regards,

T G-R

Re: SANE / simple-scan working for anyone?

[Tobias Geerinckx-Rice]

Huh,

Tobias Geerinckx-Rice wrote:
> From the sane-backends change log:
>
>  “Note 3: The Linux USB3 workaround which was added in version
>   1.0.25 is now disabled by default. If you have difficulty 
>   using
>   a scanner which previously worked, or intermittent scanner
>   availability, try setting the new environment variable
>   SANE_USB_WORKAROUND=1 before starting your frontend.”
>
> I'll try that when I'm reunited with mine.

This actually worked.

Or at least, simple-scan suddenly started scanning after launching 
it a second time, with this variable set.

Kind regards,

T G-R