some eccodes tests fail on i686 platform

The test was performed in the Fedora koji (rpm) build system.

In addition, a manual local build confirmed that the problems are not related to changes performed during packaging (such as removal of the rpath).

Version: eccodes-2.7.0

The following tests FAILED:
14 - eccodes_t_bufr_dump_encode_filter (Failed)
16 - eccodes_t_bufrdc_ref (Failed)
21 - eccodes_t_bufr_filter (Failed)
39 - eccodes_t_gts_get (Failed)
40 - eccodes_t_gts_ls (Failed)
41 - eccodes_t_gts_compare (Failed)
42 - eccodes_t_metar_ls (Failed)
43 - eccodes_t_metar_get (Failed)
44 - eccodes_t_metar_dump (Failed)
45 - eccodes_t_metar_compare (Failed)
48 - eccodes_t_sh_ieee64 (Child aborted)
91 - eccodes_t_bufr_dump_encode_fortran (Failed)
94 - eccodes_t_bufr_dump_encode_C (Failed)
96 - eccodes_t_bufr_dump_encode_python (Failed)
182 - eccodes_p_grib_get_message_offset_test (Failed)
Errors while running CTest

See also: https://bugzilla.redhat.com/show_bug.cgi?id=1562066

and: https://koji.fedoraproject.org/koji/buildinfo?buildID=1061241

The gts and metar problems seem related.
They all end in the error "no message found in <file>" even though the file used for testing clearly contains data.
While trying to debug the eccodes_t_gts_get test case I could track the issue down to the file eccodes-2.7.0-Source/src/grib_io.c
function read_any_gts, line 893:

r->read(r->read_data,buffer+already_read,message_size-already_read,&err);

This one returns with error code -1, but I have no idea why.