https://bitbucket.org/multicoreware/x265/commits/4504219210793536d921ee4e0b3058698c630bf4

diff -u -r ../x265_2.8/source/common/param.cpp ./source/common/param.cpp
--- ../x265_2.8/source/common/param.cpp	2018-05-21 08:33:10.000000000 +0000
+++ ./source/common/param.cpp	2018-06-26 03:48:16.649067505 +0000
@@ -633,7 +633,7 @@
         if (bValueWasNull)
             p->cpuid = atobool(value);
         else
-            p->cpuid = parseCpuName(value, bError);
+            p->cpuid = parseCpuName(value, bError, false);
 #endif
     }
     OPT("fps")