diff -r 397b2f4502c1 -r 3be619402d6b QTfrontend/CMakeLists.txt
--- a/QTfrontend/CMakeLists.txt	Fri Jan 11 08:08:28 2019 -0500
+++ b/QTfrontend/CMakeLists.txt	Fri Jan 11 08:51:11 2019 -0500
@@ -248,7 +248,7 @@
 endif()
 
 if(CMAKE_CXX_COMPILER MATCHES "clang*")
-    list(APPEND HW_LINK_LIBS stdc++ m)
+    list(APPEND HW_LINK_LIBS stdc++ m atomic)
 endif()
 
 if(WIN32 AND VCPKG_TOOLCHAIN)