Bug#991300: 1:0.4.30-1 is FTFBS on s390x (bytes per pixel in header is 4096 instead of 16)

[Christian Ehrhardt]

Package: gegl
Version: 1:0.4.30-1

Hi,
I saw this build fail in Debian and Ubuntu today:
https://buildd.debian.org/status/fetch.php?pkg=gegl&arch=s390x&ver=1%3A0.4.30-1&stamp=1626634928&raw=0
https://launchpadlibrarian.net/549105404/buildlog_ubuntu-impish-s390x.gegl_1%3A0.4.30-1_BUILDING.txt.gz

It comes down to two breaking testcases

118/249 gegl:composition / hdr_color FAIL 0.67s (exit status 250 or
signal 122 SIGinvalid)
150/249 gegl:composition / rgb_params FAIL 0.67s (exit status 250 or
signal 122 SIGinvalid)

I have found that on s390x the data gets corrupted and the header
eventually reports 4096 bytes per pixel (instead of the 16 it should
be).
That then breaks the imgcmp program used in the tests.

I have reported the issue upstream at:
  https://gitlab.gnome.org/GNOME/gegl/-/issues/289

The same issue is tracked in Ubuntu as:
  https://bugs.launchpad.net/gegl/+bug/1936901

-- 
Christian Ehrhardt
Staff Engineer, Ubuntu Server
Canonical Ltd