Constant libnghttp2_sys::NGHTTP2_ERR_FATAL

pub const NGHTTP2_ERR_FATAL: nghttp2_error = -900;

The errors < :enum:NGHTTP2_ERR_FATAL mean that the library is under unexpected condition and processing was terminated (e.g., out of memory). If application receives this error code, it must stop using that :type:nghttp2_session object and only allowed operation for that object is deallocate it using nghttp2_session_del().