FAQ
~~~
1. Compilation and installation was successful, but CUPS system for printer
write: 'Filter "rastertoezpl" for printer "..." not available: Permission
denied' or in state of printer job write: ".../rastertoezpl failed".
  - CUPS system don't have access to the driver. Check mode of the path and of
    the rastertoezpl filter (read and execute for all). If you use security
    system (e.g. AppArmor, SELinux) check the setting of it.

  - for AppArmor user
    If your system use AppArmor, you must check if the installed filter is
    accessible and executable from CUPS daemon over AppArmor setting. Or you
    can put AppArmor on CUPS to complain mode run
      $ sudo aa-complain /usr/sbin/cupsd
    and check if the problem is in setting of AppArmor. Edit AppArmor config
    file /etc/apparmor.d/usr.sbin.cupsd and line with permission for new
    filter
      "/usr/local/libexec/rastertoezpl/rastertoezpl Uxr,"
    add to section /usr/sbin/cupsd (of course, the path must be to file, no to
    a symbolic link!).
    
    And then activate AppArmor with:
      $ sudo aa-enforce /usr/sbin/cupsd .


2. PPD files are installed, but not in CUPS menu.
  The PPD files are installed in a path which CUPS don't walk. You can do one of
  these:
  - Create symbolic link in a path that CUPS walked to the installed directory
    with PPD files. (See parameters CREATE_PPDLINK and PPDLINK.)
  - During installation of the printer you can set the path of the PPD files.
    (See parameter PPDDIR.)
  - The PPD file selected manually.
