diff -r 11ff9b5feabb -r 1c2063701dc0 common/autoconf/toolchain.m4
--- a/common/autoconf/toolchain.m4	Wed Oct 14 16:43:12 2020 +0800
+++ b/common/autoconf/toolchain.m4	Wed Oct 14 17:44:46 2020 +0800
@@ -433,7 +433,7 @@
     COMPILER_VERSION_STRING=`$ECHO $COMPILER_VERSION_OUTPUT | \
         $SED -e 's/ *Copyright .*//'`
     COMPILER_VERSION_NUMBER=`$ECHO $COMPILER_VERSION_OUTPUT | \
-        $SED -e 's/^.* \(@<:@1-9@:>@\.@<:@0-9.@:>@*\) .*$/\1/'`
+        $SED -e 's/^.* \(@<:@1-9@:>@@<:@0-9@:>@*\.@<:@0-9.@:>@*\) .*$/\1/'`
   elif test  "x$TOOLCHAIN_TYPE" = xclang; then
     # clang --version output typically looks like
     #    Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)