在 OSX 上构建最新的 Ruby 失败:
../.././ext/psych/yaml/api.c:11:12: error: use of undeclared identifier 'YAML_VERSION_STRING'
return YAML_VERSION_STRING;
^
../.././ext/psych/yaml/api.c:21:14: error: use of undeclared identifier 'YAML_VERSION_MAJOR'
*major = YAML_VERSION_MAJOR;
^
../.././ext/psych/yaml/api.c:22:14: error: use of undeclared identifier 'YAML_VERSION_MINOR'
*minor = YAML_VERSION_MINOR;
^
../.././ext/psych/yaml/api.c:23:14: error: use of undeclared identifier 'YAML_VERSION_PATCH'
*patch = YAML_VERSION_PATCH;
为什么会这样?源码没有测试吗?