Testing on rimu with lamont's help, it seems to be an alignment issue. Setting /proc/cpu/alignment to 2 (fixup) causes the following failures:

#   Failed test 'num_segments'
#   at t/sharelite.t line 40.
#          got: '1'
#     expected: '3'
t/sharelite....NOK 11/14                                                     
#   Failed test 'frag fetch'
#   at t/sharelite.t line 43.
#          got: ''
#     expected: 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
t/sharelite....NOK 12/14                                                     
#   Failed test 'version inc'
#   at t/sharelite.t line 47.
#          got: '2'
#     expected: '4'
t/sharelite....NOK 13/14                                                     
#   Failed test 'lock'
#   at t/sharelite.t line 71.
#          got: 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXYAUS'
#     expected: '2000'
t/sharelite....NOK 14/14                                                     
#   Failed test 'version inc'
#   at t/sharelite.t line 72.
#          got: '1019'
#     expected: '2004'
# Looks like you failed 5 tests of 14.
t/sharelite....dubious                                                       
	Test returned status 5 (wstat 1280, 0x500)
DIED. FAILED tests 10-14
	Failed 5/14 tests, 64.29% okay
Failed Test   Stat Wstat Total Fail  List of Failed
-------------------------------------------------------------------------------
t/sharelite.t    5  1280    14    5  10-14
Failed 1/3 test scripts. 5/16 subtests failed.
Files=3, Tests=16,  2 wallclock secs ( 1.27 cusr +  0.09 csys =  1.36 CPU)
Failed 1/3 test programs. 5/16 subtests failed.
make: *** [test_dynamic] Error 5


Meanwhile, setting it to 3 (fixup+warn) causes one build failure to go away, and the following make test results:

(jaunty)mcasadevall@rimu:~/libipc-sharelite-perl-0.13$ make test
PERL_DL_NONLAZY=1 /usr/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(0, 'blib/lib', 'blib/arch')" t/*.t
t/00-load......ok 1/1# Testing IPC::ShareLite 0.13                           
t/00-load......ok                                                            
t/pod..........ok                                                            
t/sharelite....NOK 13/14                                                     
#   Failed test 'lock'
#   at t/sharelite.t line 71.
#          got: '1060'
#     expected: '2000'
t/sharelite....NOK 14/14                                                     
#   Failed test 'version inc'
#   at t/sharelite.t line 72.
#          got: '1064'
#     expected: '2004'
# Looks like you failed 2 tests of 14.
t/sharelite....dubious                                                       
	Test returned status 2 (wstat 512, 0x200)
DIED. FAILED tests 13-14
	Failed 2/14 tests, 85.71% okay
Failed Test   Stat Wstat Total Fail  List of Failed
-------------------------------------------------------------------------------
t/sharelite.t    2   512    14    2  13-14
Failed 1/3 test scripts. 2/16 subtests failed.
Files=3, Tests=16,  2 wallclock secs ( 1.34 cusr +  0.06 csys =  1.40 CPU)
Failed 1/3 test programs. 2/16 subtests failed.
make: *** [test_dynamic] Error 2

The default alignment on rimu and the porting boxes is 0 (ignore)