I am having the exact same test failure results on openbsd, and the archives show that some people have had similar problems, with no resolution that I have seen.
what happens if you manually run
/usr/local/apache2/bin/httpd -X -d ./t -f cont/httpd.conf
from within the toplevel mod_perl-1.99_09 directory?
It segfaults, just as you suspected. The trace appears to be in libperl.so as well:
(gdb) bt
#0 0x005de974 in Perl_hv_store_flags ()
#1 0x005e1274 in Perl_hv_fetch ()
#2 0x0058e300 in Perl_gv_fetchpv ()
#3 0x005a1d24 in S_pending_ident ()
#4 0x00592418 in Perl_yylex ()
#5 0x005ad3d4 in Perl_yyparse ()
#6 0x00614f4c in S_doeval ()
#7 0x00616550 in Perl_pp_require ()
#8 0x005e49a8 in Perl_runops_standard ()
#9 0x00588910 in Perl_call_sv ()
#10 0x0058c448 in S_call_list_body ()
#11 0x0058bfcc in Perl_call_list ()
#12 0x005b9fb8 in Perl_newATTRSUB ()
#13 0x005b4e5c in Perl_utilize ()
#14 0x005ae000 in Perl_yyparse ()
#15 0x00614f4c in S_doeval ()
#16 0x00616550 in Perl_pp_require ()
#17 0x005e49a8 in Perl_runops_standard ()
#18 0x00588910 in Perl_call_sv ()
#19 0x0058c448 in S_call_list_body ()
#20 0x0058bfcc in Perl_call_list ()
#21 0x005b9fb8 in Perl_newATTRSUB ()
#22 0x005b4e5c in Perl_utilize ()
#23 0x005ae000 in Perl_yyparse ()
#24 0x00614f4c in S_doeval ()
#25 0x00616550 in Perl_pp_require ()
#26 0x005e49a8 in Perl_runops_standard ()
#27 0x00588910 in Perl_call_sv ()
#28 0x0058c448 in S_call_list_body ()
#29 0x0058bfcc in Perl_call_list ()
#30 0x005b9fb8 in Perl_newATTRSUB ()
#31 0x005b4e5c in Perl_utilize ()
#32 0x005ae000 in Perl_yyparse ()
#33 0x00614f4c in S_doeval ()
#34 0x00616550 in Perl_pp_require ()
#35 0x005e49a8 in Perl_runops_standard ()
#36 0x00588e2c in Perl_eval_sv ()
#37 0x0058916c in Perl_require_pv ()
#38 0x00458a1c in modperl_require_file ()
#39 0x004549fc in modperl_config_apply_PerlRequire ()
#40 0x00452864 in modperl_startup ()
#41 0x00452eb8 in modperl_hook_init ()
#42 0x00455bbc in modperl_cmd_load_module ()
#43 0x000363a4 in invoke_cmd (cmd=0x46a9dc, parms=0xbffffb30, mconfig=0x343708, args=0x34e220 "TestDirective::perlloadmodule") at config.c:828
#44 0x00036a64 in ap_walk_config_sub (current=0x34e200, parms=0xbffffb30, section_vector=0x3020a8) at config.c:1082
#45 0x00036b04 in ap_walk_config (current=0x34e200, parms=0xbffffb30, section_vector=0x3020a8) at config.c:1121
#46 0x00037678 in ap_process_config_tree (s=0x300c58, conftree=0x3439c8, p=0x2fe548, ptemp=0x33e058) at config.c:1594
#47 0x00023f98 in main (argc=6, argv=0xbffffccc) at main.c:638
#48 0x000028bc in _start (argc=6, argv=0xbffffccc, envp=0xbffffce8) at /SourceCache/Csu/Csu-45/crt.c:267
#49 0x0000273c in start ()
-=Eric
