 private func parseBPFArch<S: StringProtocol>(_ archName: S) -> Triple.Arch {
   switch archName {
   case "bpf":
-    fatalError("Unimplemented - need to determine host endianness")
+    // FIXME: need to determine host endianness
+    return .unknown
   case "bpf_be", "bpfeb":
     return .bpfeb
   case "bpf_le", "bpfel":

/// Triple - Helper for working with autoconf configuration names. For
/// historical reasons, we also call these 'triples' (they used to contain
/// exactly three fields).
///
/// Configuration names are strings in the canonical form:
///   ARCHITECTURE-VENDOR-OPERATING_SYSTEM
/// or
///   ARCHITECTURE-VENDOR-OPERATING_SYSTEM-ENVIRONMENT

/// Clients that need to handle the non-canonical triples that users often
/// specify should use the normalize method.
///
/// See autoconf/config.guess for a glimpse into what target triples
/// look like in practice.
///
/// This is a port of https://github.com/apple/swift-llvm/blob/stable/include/llvm/ADT/Triple.h
