An experiment in Hare attempts to read errno without a C wrapper, starting from the fact that the macro is not a portable exported function. It redirects standard error to a temporary file during initialization and matches perror output against a precomputed strerror table to recover an error number. This exploratory technique depends on standard-error handling, locale, thread sharing and fixed-range assumptions; it is not a general production solution. Related discussion points to a small C wrapper as the practical approach and highlights implementation-specific POSIX headers.