Every catch unreachable, orelse unreachable and syscall assert outside tests is a real refusal or says why it cannot fire

A sweep for round 23's crash: a run's answer (pty/run) was bufPrint'd into 48 bytes with catch unreachable, so a foreground program's long name (macOS gives up to 32 bytes) panicked; it now cuts at the room, keeping its newline, in 96 bytes. The rest were numbers into buffers sized for them, a braille codepoint, pthread calls on the queue's own mutex, and pdf_view's resolved outline entries: each now carries a one-line comment saying why it cannot fire.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/9p_io.zig b/src/9p_io.zig
index 560c4ed6..91240b57 100644
--- a/src/9p_io.zig
+++ b/src/9p_io.zig
@@ -1638,6 +1638,7 @@ extern "c" fn unsetenv(name: [*:0]const u8) c_int;
 
 pub fn start(io: std.Io, gpa: std.mem.Allocator, core: *pardes.Pardes) ?*Listener {
     var name: [16]u8 = undefined;
+    // unreachable: a u32 is at most 10 digits
     const fallback = std.fmt.bufPrint(&name, "{d}", .{@as(u32, @intCast(libc.getpid()))}) catch unreachable;
     return listen(io, gpa, core, core.opts.ninep_name, fallback, core.opts.ninep_tcp, core.opts.ninep_quic) orelse {
         core.reportError(0, "9p listener", error.ListenFailed);