Tty and Shell refuse a directory: not a shell

A directory passes access(X_OK), so Tty /etc made a pane whose shell
exited 127 and Shell /etc was taken. The shell lookup now refuses a
directory, and both say "not a shell: /etc is a directory" (Tty and
Shell share one refusal, host_io.Shell.refusal). shellset's golden takes
the shared wording (re-recorded by name).

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

1 files changed, 3 insertions, 2 deletions

diff --git a/docs/config.md b/docs/config.md
index 95f034d7..ebedc4d0 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -49,8 +49,9 @@ opens the file. Shell follows the same requested/effective/pending model as
 Font. `Default shell` is the one used while no `Shell` is set: `$SHELL`, the
 user's login shell, else `/bin/sh` (also when `$SHELL` names nothing
 executable); an explicit `Shell` overrides it. `Shell <name or path>` is
-refused, `Shell: <it>: no executable by that name`, unless it names an
-executable (a bare name is looked for in the usual bin directories), and a
+refused unless it names an executable file (`Shell: no shell "x" (...)`, or
+`Shell: not a shell: /etc is a directory`; a bare name is looked for in the
+usual bin directories), as `Tty <shell>` is, and a
 bare `Shell` goes back to the default. The root ctl reads `Shell <the one the
 next terminal runs>`. `Shell
 effective (last spawn)` is the executable the native host really chose after