This bug was originally posted as https://gitlab.gnome.org/GNOME/epiphany/issues/957 but I was advised to put this here.
On a fresh installation of Arch Linux with Gnome 3.34.0 I can not make Epiphany to print anything. Printers are setup correctly and work from other applications. I have attached 3 screenshots:
When I press Ctrl-p or select printing from the menu, the Gnome print dialog comes up as expected.
When I select a printer (in my case "netbrother" or PDF) and click Print, the print dialog disappears and the error message "Printer not found" is shown.
When I select "Print to File" and click Print, the print dialog disappears and the error "No such file or directory" is shown.
Does this happen with sandboxing disabled?
It works with WEBKIT_FORCE_SANDBOX=0, so I guess it's trying to print from the web process? That's weird.
Would be good to fix bug #192748 at the same time. Switching WebKitPrintOperation to use either GtkPrintOperation or the printing portal directly should suffice for both bugs.
The dialog runs in the UI process, and the generated settings are sent to the web process. In the web process we use GtkPrintJob, which requires a GtkPrinter object, so we also use gtk_enumerate_printers() to find the selected printer. I guess gtk_enumerate_printers it's failing, that's why the error is printer not found. GtkPrintJob will probably fail too if we get the printer, though.