Problem:
When a command is not found or not executable, the error message gives
no indication about what command was actually tried.
Solution:
Always append the command name to the error message.
BEFORE:
E5108: Error executing lua …/_system.lua:248: ENOENT: no such file or directory
AFTER:
E5108: Error executing lua …/_system.lua:249: ENOENT: no such file or directory: "foo"
fix#33445