call and read are live, and the fixture for one of them is broken

obSCEne reports both implemented - the serving build announces call,read,report where it announced report. Consumers built.

Client::call(address, args) and Client::read(address, length) send hexadecimal and handle the outcomes the feedback was explicit about:

• A fatal address is called, not refused. Malformed arguments are refused; a well-formed address that happens to be fatal is executed, and the probe dies doing it - which arrives as an acknowledgement with no result. Null is called rather than rejected, because "what does this platform do when you call null" is a real question with a real answer.
• A bad read address has two legitimate answers. A platform that can test before touching answers unmapped; one that cannot faults, and that is a death. Today's serving build does not pre-validate. Both are handled and both are tested, because which build is on the other end is not knowable from here.

bytes records are parsed and reassembled in offset order.

Surprises

The captured 06-read.txt carries an odd number of hexadecimal digits. It requests 0x20 bytes - thirty-two, so sixty-four digits - and the record holds sixty-five. One character spare, so the run cannot be a whole number of bytes.

The decoder refuses it and counts it. Rounding would put a value in a buffer that nothing observed, and a buffer is exactly where an invented byte is least visible; silently dropping the run would be worse, because a caller would receive a shorter buffer that looks complete. Pinned as a test asserting the defect, so that correcting the capture upstream fails here and whoever fixes it is told to replace the test with one asserting the bytes decode.

Found by writing a decoder that refuses the impossible rather than one that copes.

The thing that made both consumers cheap was already there. The client is generic over any stream, so call returning a value, call 0x0 dying, read returning ELF magic and read of a bad address dying are four tests over in-memory buffers - none needing a socket, a console, or the emulator path that currently cannot reach its own listen call.