raise_if_dead(fix[FileNotFoundError]): Catch FileNotFoundError for invalid tmux_bin

why: subprocess.check_call raises FileNotFoundError when tmux_bin points to
a nonexistent path, leaking a raw exception instead of TmuxCommandNotFound.
what:
- Wrap subprocess.check_call in try/except FileNotFoundError
- Add test_tmux_bin_invalid_path_raise_if_dead test case

Author: tony

src/libtmux/server.py

@@ -236,7 +236,10 @@ def raise_if_dead(self) -> None:
         if self.config_file:
             cmd_args.insert(0, f"-f{self.config_file}")
 
-        subprocess.check_call([resolved, *cmd_args])
+        try:
+            subprocess.check_call([resolved, *cmd_args])
+        except FileNotFoundError:
+            raise exc.TmuxCommandNotFound from None
 
     #
     # Command

tests/test_server.py

@@ -441,3 +441,12 @@ def test_tmux_bin_invalid_path() -> None:
     s = Server(tmux_bin="/nonexistent/tmux")
     with pytest.raises(exc.TmuxCommandNotFound):
         s.cmd("list-sessions")
+
+
+def test_tmux_bin_invalid_path_raise_if_dead() -> None:
+    """Invalid tmux_bin raises TmuxCommandNotFound in raise_if_dead()."""
+    from libtmux import exc
+
+    s = Server(tmux_bin="/nonexistent/tmux")
+    with pytest.raises(exc.TmuxCommandNotFound):
+        s.raise_if_dead()