--- llbuild/lib/llvm/Support/CMakeLists.txt.orig	2016-03-15 20:15:59 UTC
+++ llbuild/lib/llvm/Support/CMakeLists.txt
@@ -41,3 +41,7 @@ raw_ostream.cpp
 if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
   target_link_libraries(llvmSupport pthread dl)
 endif()
+
+if(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
+  target_link_libraries(llvmSupport pthread execinfo)
+endif()
