A Save into a directory that is not there says no such directory, ENOENT

It failed EIO with `file not found`, which named no file that was
missing. It says `Save <path>: no such directory`, and a late failure
saying `no such` answers ENOENT, as a builtin's does.

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

1 files changed, 5 insertions, 1 deletions

diff --git a/src/9p_io.zig b/src/9p_io.zig
index 2130db27..4c9c9bcf 100644
--- a/src/9p_io.zig
+++ b/src/9p_io.zig
@@ -315,7 +315,11 @@ pub const Listener = struct {
         // ponytail: one slot, so a failure of another client's effects that
         // settle in the same wait is told to this write too.
         if (l.core == core and core.fs.late_failure_len != 0) {
-            const failed = pardes.ctlfs.failText(req.tag, pardes.ctlfs.E.IO, core.fs.late_failure[0..core.fs.late_failure_len]);
+            const late = core.fs.late_failure[0..core.fs.late_failure_len];
+            // What is not there (`no such directory`) is ENOENT, as a
+            // builtin's failure saying so is (ctl.failureErrno).
+            const errno = if (std.mem.indexOf(u8, late, "no such") != null) pardes.ctlfs.E.NOENT else pardes.ctlfs.E.IO;
+            const failed = pardes.ctlfs.failText(req.tag, errno, late);
             // Its err record says it (the path in it); the msg the failure
             // was also said as goes, as a builtin's failing a write does.
             pardes.ctlfs.events.dropMessage(core, core.fs.late_failure[0..core.fs.late_failure_len]);