build of dovecot 2.2.6 fails on 32-bit big endian arches (ppc, s390) because there is a segfault in the test suite, same error happened when I tried a rebuild of Fedora srpm in RHEL 7 buildroot.

from build.log
...
http url parse/create [6] ............................................ : ok
http url parse/create [7]: parse  http://www.example.com/%23shared/news  : ok
http url parse/create [7]: create http://www.example.com/%23shared/news  : ok
http url parse/create [7] ............................................ : ok
http url parse/create [8]: parse  http://www.example.com/query.php?name=Hendrik%20Visser  : ok
http url parse/create [8]: create http://www.example.com/query.php?name=Hendrik%20Visser  : ok
http url parse/create [8] ............................................ : ok
http url parse/create [9]: parse  http://www.example.com/network.html#IMAP%20Server  : ok
http url parse/create [9]: create http://www.example.com/network.html#IMAP%20Server  : ok
http url parse/create [9] ............................................ : ok
0 / 578 tests failed
/bin/sh: line 1: 12328 Segmentation fault      (core dumped) ./$bin
make[2]: Leaving directory `/builddir/build/BUILD/dovecot-2.2.6/src/lib-http'
make[2]: *** [check-test] Error 1
make[1]: *** [check-recursive] Error 1
make[1]: Leaving directory `/builddir/build/BUILD/dovecot-2.2.6/src'

full logs available at
http://ppc.koji.fedoraproject.org/koji/taskinfo?taskID=1460140
http://s390.koji.fedoraproject.org/koji/taskinfo?taskID=1238050

Version-Release number of selected component (if applicable):
dovecot-2.2.6-1.fc{19,20}