I'm going to mark this broken for now, no point wasting cpu cycles during build.
This is now failing here, instead of segfault during build: S=/usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2 && I=$S/instdir && W=$S/workdir && mkdir -p $W/CxxObject/bridges/source/cpp_uno/gcc3_linux_intel/ $W/Dep/CxxObject/bridges/source/cpp_uno/gcc3_linux_intel/ && cd /usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2 && c++ -DBOOST_ERROR_CODE_HEADER_ONLY -DBOOST_SYSTEM_NO_DEPRECATED -DCPPU_ENV=gcc3 -DINTEL -DNDEBUG -DOPENBSD -DOPTIMIZE -DOSL_DEBUG_LEVEL=0 -DUNIX -DUNX -DX86 -D_PTHREADS -D_REENTRANT -D_THREAD_SAFE -DHAVE_GCC_VISIBILITY_FEATURE -fvisibility=hidden -Wall -Wno-missing-braces -Wnon-virtual-dtor -Wendif-labels -Wextra -Wundef -Wunused-macros -fmessage-length=0 -fno-common -fno-stack-protector -pipe -Wimplicit-fallthrough -fstack-protector-strong -fPIC -Wshadow -Woverloaded-virtual -std=gnu++14 -DEXCEPTIONS_ON -fexceptions -O2 -pipe -fno-omit-frame-pointer -fno-strict-aliasing -mno-avx -DLIBO_INTERNAL_ONLY -c $S/bridges/source/cpp_uno/gcc3_linux_intel/except.cxx -o $W/CxxObject/bridges/source/cpp_uno/gcc3_linux_intel/except.o -I$S/bridges/source/cpp_uno/gcc3_linux_intel/ -I$S/bridges/inc -I$S/include -I/usr/local/include -I/usr/local/jdk-1.8.0/include -I/usr/local/jdk-1.8.0/include/openbsd -I$S/config_host -I$W/UnoApiHeadersTarget/udkapi/comprehensive [build CXX] bridges/source/cpp_uno/gcc3_linux_intel/uno2cpp.cxx /usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2/bridges/source/cpp_uno/gcc3_linux_intel/cpp2uno.cxx:327:9: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough] default: ^ /usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2/bridges/source/cpp_uno/gcc3_linux_intel/cpp2uno.cxx:327:9: note: insert 'SAL_FALLTHROUGH;' to silence this warning default: ^ SAL_FALLTHROUGH; /usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2/bridges/source/cpp_uno/gcc3_linux_intel/cpp2uno.cxx:327:9: note: insert 'break;' to avoid fall-through default: ^ break; /usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2/bridges/source/cpp_uno/gcc3_linux_intel/except.cxx:164:32: error: unknown type name '__si_class_type_info' rtti = new __si_class_type_info( ^ /usr/obj/ports/libreoffice-5.2.7.2/libreoffice-5.2.7.2/bridges/source/cpp_uno/gcc3_linux_intel/except.cxx:170:32: error: unknown type name '__class_type_info' rtti = new __class_type_info( strdup( rttiName ) ); ^ 1 warning generated. 2 errors generated.