Grab the release in debug mode if there is no debug when not on msvc

cmake/modules/FindOpenVDB.cmake

@@ -235,6 +235,10 @@ foreach(COMPONENT ${OpenVDB_FIND_COMPONENTS})
 
     set(OpenVDB_${COMPONENT}_LIBRARY ${OpenVDB_${COMPONENT}_LIBRARY_${_BUILD_TYPE}})
 
+    if (NOT MSVC AND NOT OpenVDB_${COMPONENT}_LIBRARY)
+      set(OpenVDB_${COMPONENT}_LIBRARY ${OpenVDB_${COMPONENT}_LIBRARY_RELEASE})
+    endif ()
+
     list(APPEND OpenVDB_LIB_COMPONENTS ${OpenVDB_${COMPONENT}_LIBRARY})
 
     if(OpenVDB_${COMPONENT}_LIBRARY)