extconf.rb in jsonnet-0.5.1

- old
+ new

@@ -74,9 +74,16 @@
   recipe.cook
   # I tried using recipe.activate here but that caused this file to build ok
   # but the makefile to fail. These commands add the necessary paths to do both
   $LIBPATH = ["#{recipe.path}/lib"] | $LIBPATH
   $CPPFLAGS << " -I#{recipe.path}/include"
+
+  # jsonnet_wrap extension must be linked with c++ stdlib because
+  # the C++ library Rapid YAML is being statically linked.
+  rbconfig = RbConfig::MAKEFILE_CONFIG
+  if rbconfig['LDSHAREDXX']
+    rbconfig['LDSHARED'] = rbconfig['LDSHAREDXX']
+  end
 end
 
 abort 'libjsonnet.h not found' unless have_header('libjsonnet.h')
 abort 'libjsonnet not found' unless have_library('jsonnet')
 have_header('libjsonnet_fmt.h')