Index: devel/gdb/Makefile
===================================================================
--- devel/gdb/Makefile
+++ devel/gdb/Makefile
@@ -36,18 +36,22 @@
 
 ONLY_FOR_ARCHS=	i386 amd64 powerpc powerpc64	# untested elsewhere, might work
 
-OPTIONS_DEFINE=	DEBUG EXPAT GDB_LINK GUILE KGDB PYTHON THREADS TUI
+OPTIONS_DEFINE=	DEBUG EXPAT GDB_LINK GUILE KGDB PYTHON TUI
 
-OPTIONS_DEFAULT=	GDB_LINK KGDB THREADS TUI PORT_READLINE
+OPTIONS_DEFAULT=	GDB_LINK KGDB THREAD_DB_THREAD TUI PORT_READLINE
 
-OPTIONS_SINGLE=	READLINE
+OPTIONS_SINGLE=	READLINE THREADS
 OPTIONS_SINGLE_READLINE=	BASE_READLINE BUNDLED_READLINE PORT_READLINE
+OPTIONS_SINGLE_THREADS=		THREAD_DB_THREAD PTRACE_THREAD NONE_THREAD
 
 GDB_LINK_DESC=		Create ${PREFIX}/bin/gdb symlink
 KGDB_DESC=		Kernel Debugging Support
 BASE_READLINE_DESC=	from base system (experimental)
 BUNDLED_READLINE_DESC=	from gdb distfile
+NONE_THREAD_DESC=	No thread debugging support
 PORT_READLINE_DESC=	from devel/readline port
+PTRACE_THREAD_DESC=	Use ptrace() for thread debugging (experimental)
+THREAD_DB_THREAD_DESC=	Use libthread_db for thread debugging
 TUI_DESC=		Text User Interface enabled
 
 OPTIONS_SUB=	yes
@@ -80,14 +84,17 @@
 post-patch:
 	@${REINPLACE_CMD} -e 's|$$| [GDB v${PORTVERSION} for FreeBSD]|' \
 		${WRKSRC}/gdb/version.in
-.if ${PORT_OPTIONS:MTHREADS}
+.if ${PORT_OPTIONS:MTHREAD_DB_THREAD}
 	@${CP} ${FILESDIR}/fbsd-threads.c ${WRKSRC}/gdb/
 	@${PATCH} ${PATCH_ARGS} < ${FILESDIR}/extrapatch-threads
 .endif
+.if ${PORT_OPTIONS:MPTRACE_THREAD}
+	@${PATCH} ${PATCH_ARGS} < ${FILESDIR}/extrapatch-threads-ptrace
+.endif
 .if ${PORT_OPTIONS:MKGDB}
 	@${CP} -r ${FILESDIR}/kgdb/*.[ch] ${WRKSRC}/gdb/
 	@${PATCH} ${PATCH_ARGS} < ${FILESDIR}/extrapatch-kgdb
-.if ${PORT_OPTIONS:MTHREADS}
+.if ${PORT_OPTIONS:MTHREAD_DB_THREAD}
 	@${PATCH} ${PATCH_ARGS} < \
 	    ${FILESDIR}/extrapatch-kgdb-configure.tgt-threads
 .else