--- src/libs/xpcom18a4/Config.kmk.orig	2020-07-10 02:59:16.000000000 +1000
+++ src/libs/xpcom18a4/Config.kmk	2020-08-21 01:32:58.696410000 +1000
@@ -46,6 +46,7 @@
 TEMPLATE_XPCOM_CXXFLAGS.release    = -O
 TEMPLATE_XPCOM_CXXFLAGS.profile    = -O
 TEMPLATE_XPCOM_CXXFLAGS.darwin     = -fpascal-strings -fshort-wchar -fno-common -fno-rtti $(VBOX_DARWIN_DEF_SDK_CXXFLAGS)
+TEMPLATE_XPCOM_CXXFLAGS.bsdsunix   = -pthread
 TEMPLATE_XPCOM_CXXFLAGS.freebsd    = -pthread
 TEMPLATE_XPCOM_CXXFLAGS.linux      = -pthread
 TEMPLATE_XPCOM_CXXFLAGS.solaris    = -fno-omit-frame-pointer # for now anyway.
@@ -55,6 +56,7 @@
 TEMPLATE_XPCOM_CFLAGS.amd64        = -m64
 TEMPLATE_XPCOM_CFLAGS.release      = -O
 TEMPLATE_XPCOM_CFLAGS.profile      = -O
+TEMPLATE_XPCOM_CFLAGS.bsdsunix     = -pthread
 TEMPLATE_XPCOM_CFLAGS.freebsd      = -pthread
 TEMPLATE_XPCOM_CFLAGS.linux        = -pthread -ansi
 TEMPLATE_XPCOM_CFLAGS.solaris      = -fno-omit-frame-pointer # for now anyway.
@@ -73,6 +75,7 @@
 TEMPLATE_XPCOM_DEFS.amd64          = HAVE_VA_LIST_AS_ARRAY HAVE_VA_COPY VA_COPY\(a\,b\)=__builtin_va_copy\(a\,b\)
 TEMPLATE_XPCOM_DEFS.darwin         = OSTYPE=\"Darwin8.8.1\" OSARCH=\"Darwin\" XP_UNIX=1 XP_MACOSX=1 TARGET_CARBON=1 HAVE_VISIBILITY_ATTRIBUTE=1 DARWIN=1 $(TEMPLATE_VBOXR3NP_DEFS.darwin)
 TEMPLATE_XPCOM_DEFS.darwin.amd64   = VBOX_MACOSX_FOLLOWS_UNIX_IO
+TEMPLATE_XPCOM_DEFS.bsdsunix       = OSTYPE=\"BSDSUniX1+\"  OSARCH=\"BSDSUniX\" XP_UNIX=1 BSDSUNIX=1 HAVE_VISIBILITY_ATTRIBUTE=1
 TEMPLATE_XPCOM_DEFS.freebsd        = OSTYPE=\"FreeBSD5+\"   OSARCH=\"FreeBSD\" XP_UNIX=1 FREEBSD=1 HAVE_VISIBILITY_ATTRIBUTE=1
 TEMPLATE_XPCOM_DEFS.linux          = OSTYPE=\"Linux2.6\"    OSARCH=\"Linux\"  XP_UNIX=1 _GNU_SOURCE HAVE_VISIBILITY_ATTRIBUTE=1 ## @todo LINUX=1
 # Don't define BSD_SELECT because bsdselect() from kLIBC <= 0.6.3 has problems on SMP
@@ -166,6 +169,7 @@
 	$(VBox-xpcom-ipcshared_1_TARGET) \
 	$(VBoxXPCOM_1_TARGET) \
 	$(TEMPLATE_XPCOM_LIBS)
+TEMPLATE_XPCOMEXE_LIBS.bsdsunix    = $(LIB_PTHREAD)
 TEMPLATE_XPCOMEXE_LIBS.freebsd     = $(LIB_PTHREAD)
 TEMPLATE_XPCOMEXE_LIBS.linux       = dl $(LIB_PTHREAD)
 TEMPLATE_XPCOMEXE_LDFLAGS.darwin   = -bind_at_load $(filter-out -current_version -compatibility_version $(VBOX_VERSION_MAJOR).$(VBOX_VERSION_MINOR).$(VBOX_VERSION_BUILD),$(TEMPLATE_XPCOM_LDFLAGS.darwin))