Every EINVAL or ENOENT refusal a unit test meets must say its errno in words a 9ns mount maps back: pardes re-pins cloud9, whose fs.enameErrno knows acme's address and argument refusals

The tests' request helper asks cloud9's fs.enameErrno, the rules 9ns
turns a refusal's words back into an errno with, for every EINVAL and
ENOENT a request is refused with, and fails the test when a mount
would hear another (EIO, mostly): "this pane has no text to address"
was one. The re-pinned cloud9 maps acme's own refusals, which pardes
keeps in acme's words: no match for regexp, address out of range,
addresses out of order, range past end of body and the rest.

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

2 files changed, 10 insertions, 2 deletions

diff --git a/build.zig.zon b/build.zig.zon
index a478df6e..5efe9c28 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -9,8 +9,8 @@
         // read-only HTTPS URL is what a manifest can carry. Re-pin with
         // `zig fetch --save=cloud9 git+https://git.sr.ht/~gbrls/cloud9#<commit>`.
         .cloud9 = .{
-            .url = "git+https://git.sr.ht/~gbrls/cloud9#12d78be492351e29144daa379232bbd955b47631",
-            .hash = "cloud9-0.1.0-yt86qjoTHgAqXvz1h23WqTagtZNodmM5lkWFZ7Ld_880",
+            .url = "git+https://git.sr.ht/~gbrls/cloud9#552584ad79448988646231c7993a36e55b0e8c05",
+            .hash = "cloud9-0.1.0-yt86qlkdHgCC4CRZQA1ttzUYpZ07PoIxzIysTOSSbmqW",
         },
         // Pinned to the exact libvaxis commit ghostty is built against, so it
         // is compatible with ghostty's uucode configuration (the one we share
diff --git a/src/ninep/testing.zig b/src/ninep/testing.zig
index b8eaa02b..a35a9cf0 100644
--- a/src/ninep/testing.zig
+++ b/src/ninep/testing.zig
@@ -3,6 +3,7 @@
 const std = @import("std");
 const pardes = @import("../pardes.zig");
 const tree = @import("tree.zig");
+const cloud9 = @import("cloud9");
 
 const Pardes = pardes.Pardes;
 pub const Req = tree.Req;
@@ -33,6 +34,13 @@ pub const Answer = struct {
 pub fn call(p: *Pardes, req: Req) Answer {
     var ans: Answer = .{};
     ans.reply = p.serveFs(req);
+    // An EINVAL or ENOENT refusal says so in words a 9ns mount maps back
+    // to it (cloud9's enameErrno), or a shell through the mount hears EIO.
+    const said = ans.reply;
+    if (said.status == .err and said.ename.len > 0 and (said.errno == E.INVAL or said.errno == E.NOENT) and cloud9.fs.enameErrno(said.ename) != said.errno) {
+        std.debug.print("a mount reads this refusal as errno {d}, not {d}: \"{s}\"\n", .{ cloud9.fs.enameErrno(said.ename), said.errno, said.ename });
+        @panic("a refusal's words do not say its errno");
+    }
     ans.bytes = p.fsPayload(ans.reply);
     while (p.nextEffect()) |e| switch (e) {
         .save_file, .save_text => ans.saved = true,