Given the date, it sounds like we have an emergency situation. I'm really stuck here. My only known access to a big endian is an emulator with Wheezy.
http://create.stephan-brumme.com/big-endian/ That's good enough for checking suspicious parts of Leptonica. I tried and found nothing. But it is not good enough to check Tesseract 4.0. Your OCRMyPdf s390 test provides strong evidence that Tesseract is broken on big endian. http://autopkgtest.ubuntu.com/packages/o/ocrmypdf/bionic/s390x However, if I wipe out that package on big-endian, it will cause a cascading dependency failure affecting hundreds of other packages. Not great to do 36 hours before release. Recommend we talk in real time. Will send you contact details by private email.
