server.Server.run_shell

The command runs in tmux's own environment, not the caller's. Output lines are [ TmuxText ] because a shell can emit any bytes.

Errors

Returns an error when tmux refuses the command.

Also refuses outright on tmux 3.3, 3.3a, and 3.4, with Error::CapabilityDefective . Those releases send run-shell output into a pane's copy-mode buffer instead of to the client, and still exit zero, so the command appears to have produced nothing. Reporting an empty listing there would be a wrong answer the caller could not detect. 3.2a and 3.5 onwards are unaffected.