--- lib/nn/CMakeLists.txt.orig	2019-06-01 23:24:33 UTC
+++ lib/nn/CMakeLists.txt
@@ -1,5 +1,6 @@
 # lib/nn/CMakeLists.txt for PLplot
 # Copyright (C) 2006-2019 Alan W. Irwin
+# Patch borrowed from https://sourceforge.net/p/plplot/plplot/ci/52479b8830ee02900b41fe3ec947aed6b1841a48/
 #
 # This file is part of PLplot.
 #
@@ -48,19 +49,8 @@ if(PL_HAVE_QHULL)
       )
   endif(HAS_LIBQHULL_INCLUDE)
 
-  set_source_files_properties(
-    ${csironn_LIB_SRCS}
-    PROPERTIES
-    COMPILE_FLAGS "-I${QHULL_INCLUDE_DIRS}"
-    )
-
-  set(csironn_LINK_LIBRARIES ${QHULL_LIBRARIES})
-  if(MATH_LIB)
-    list(APPEND csironn_LINK_LIBRARIES ${MATH_LIB})
-  endif(MATH_LIB)
-
   set(LIB_INSTALL_RPATH ${QHULL_RPATH})
-  configure_library_build(csironn "" "${csironn_LIB_SRCS}" "${csironn_LINK_LIBRARIES}" "${QHULL_RPATH}")
+  configure_library_build(csironn "" "${csironn_LIB_SRCS}" Qhull::qhull_r "${QHULL_RPATH}")
 
   set(nn_DOCFILES
     README