Check attribute flags: controlling extended attribute behavior. Normally, attribute checks include looking in the /etc (or system equivalent) directory for a gitattributes file. Passing the GIT_ATTR_CHECK_NO_SYSTEM flag will cause attribute checks to ignore that file. Passing the GIT_ATTR_CHECK_INCLUDE_HEAD flag will use attributes from a .gitattributes file in the repository at the HEAD revision. Passing the GIT_ATTR_CHECK_INCLUDE_COMMIT flag will use attributes from a .gitattributes file in a specific commit.