Tty with a shell that is not there says so, and never sets the caller's shell

Tty /nonexistent or Tty fsh started the host's fallback shell without a word,
and when spawnTty made no pane, the argument became the calling pane's shell.
Tty now looks the shell up first and fails 'Tty: no shell "fsh"' when it is
neither a name on the usual paths nor a path to one; spawnTty answers the pane
it made, the one given the shell, and says why when it made none. The lookup
(host_io Shell.find) gives the turn up around its access() calls, since a
typed path may be under a mount this editor serves, and forkShell copies the
pane's shell before looking it up and checks the pane is still its own after.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/test/panes.zig b/test/panes.zig
index d0551cfc..662ea3a5 100644
--- a/test/panes.zig
+++ b/test/panes.zig
@@ -920,7 +920,7 @@ const TtySelectionTests = struct {
                 const p = try Pardes.init(std.testing.allocator, .{ .tty_only = true, .cols = 40, .rows = 24 });
                 defer p.deinit();
                 p.presentation.enabled = false;
-                pardes.exec.spawnTty(p, 0);
+                _ = pardes.exec.spawnTty(p, 0);
                 for (p.panes[0..2]) |slot| {
                     slot.?.body.mode = .tty;
                     slot.?.tty_filter = false;