make check / grub_func_test issues

[Daniel Axtens]

Hi all,

I'm having some trouble with the grub tests run by `make check`.

In particular, grub_func_test is failing for me in every configuration I
try. I've tried various combinations of:

 - master, grub-2.04 and grub-2.02 tags, as well as the grub-2.04
   tarball.

 - configuring for platform emu and platform i386-pc

 - on a Ubuntu 19.10 host and in a 16.04 docker container

I keep having failures with the cmdline_cat test and the gfxmenu tests
within grub_func_test - the video checksums don't match. The images all
look OK to me, so I'm not quite sure what the problem is, and we don't
ship known-good images for me to compare against.

Is this supposed to work? If so are there any tricks to getting it to
work?

Regards,
Daniel