Comment 7 for bug 1787289

Downgrading hp-plugin only works if I also downgrade hplip. The whole point is that the current version of hplip uses the new libImageProcessor and it doesn't work with the matching version of hplip-plugin on Arch Linux.

The Arch user that came up with the patch had made this comment which may help you understand this issue:

loqs
Member
Registered: 2014-03-06
Posts: 5,465
prnt/hpcups/HPCupsFilter.cpp 644: DEBUG: SHIVA inside the while loopprnt/hpcups/HPCupsFilter.cpp 648: DEBUG: imageProcessorStartPage failed result = 2
STATE: +connecting-to-device
STATE: +hplip.plugin-error
prnt/hpcups/HPCupsFilter.cpp 490: m_Job initialization failed with error = 48
With the updated package imageProcessor is now being used but is failing. Unfortunately ImageProcessor is a binary blob and the hplip.plugin is another binary blob.
Some interaction between these two black boxes results in the issue. Raise it upstream?
Edit:

          dbglog("DEBUG: SHIVA inside the while loop");

          IMAGE_PROCESSOR_ERROR result = imageProcessorStartPage(imageProcessor, &cups_header);
          if (result != IPE_SUCCESS){
              dbglog("DEBUG: imageProcessorStartPage failed result = %d\n", result);
          }

          current_page_number++;

          if (current_page_number == 1) {

              if (startPage(&cups_header) != NO_ERROR) {
                  return JOB_CANCELED;
              }

              if (m_JA.pre_process_raster) {
                  // CC ToDo: Why pSwapedPagesFileName should be sent as a parameter?
                      // Remove if not required to send it as parameter
                  err = m_Job.preProcessRasterData(&cups_raster, &cups_header, hpPreProcessedRasterFile);
                  if (err != NO_ERROR) {
                      if (m_iLogLevel & BASIC_LOG) {
                          dbglog ("DEBUG: Job::StartPage failed with err = %d\n", err);
                      }
                      ret_status = JOB_CANCELED;
                      break;
                  }
              }