Function lc_last_error 

#[unsafe(no_mangle)]
pub extern "C" fn lc_last_error() -> *const c_char

Thread-local last-error string from this thread’s most recent lc_knearest.

Returns a pointer to a NUL-terminated UTF-8 C string, or NULL if the last lc_knearest on this thread succeeded, or if none has failed yet. lc_version does not read or write the slot. Distinct threads have independent slots. The pointer is valid until the next lc_knearest on this thread. Do not free it.