[cups.general] /usr/libexec/cups/backend/usb failed

[Grant]

>> Yes, you should have no problems sending jobs from 1.5.2 to 1.6.1.  Just keep in mind that if you are using CUPS browsing for printer sharing on the 1.5.2 machine, it is no longer supported in 1.6.x...
>
> I gave it a try and I'm told there is a long printing delay now.
> Apparently it's up to 4-5 minutes for a 4-page PDF.  I've upgraded the
> client to 1.6.1 and I'll know if that helped soon.
>
> I get these from the server error_log on cupsd restart now:
>
> CreateProfile failed: org.freedesktop.DBus.Error.ServiceUnknown:The
> name org.freedesktop.ColorManager was not provided by any .service
> files
> CreateDevice failed: org.freedesktop.DBus.Error.ServiceUnknown:The
> name org.freedesktop.ColorManager was not provided by any .service
> files
>
> and this in the same log with each print, although Google says this
> was due to the mismatch in server/client cups versions and not a
> problem:
>
> Unexpected 'document-format' operation attribute in a Create-Job request.
>
> Do you know what might be causing the delay and if upgrading the
> client to 1.6.1 should fix it?
>
> - Grant

Both the client and server are on cups-1.6.1 now.  A Brother laser
printer is printing PDF files fine and a Zebra LP2844 is printing EPL
files fine, but there is a 10-second delay between ZPL labels with a
Zebra LP2844-Z when there was no delay with the client and server on
cups-1.5.2.  The ZPL label is printed like this:

system(qq{/bin/echo "^XA
^MNN
^LL235
^FO290,60^A0N,125,70^FD$sku^FS
^XZ" | /usr/bin/lpr -l -P Zebra_LP_2844-Z_4x1});

There is nothing in the cups error_log.  Can I debug this?

- Grant