--- /dev/null
+error[E0308]: mismatched types
+ --> $DIR/external_subcommand_wrong_type.rs:13:15
+ |
+13 | Other(Vec<CString>)
+ | ^^^^^^^ expected struct `std::ffi::CString`, found struct `std::ffi::OsString`
+ |
+ = note: expected struct `std::vec::Vec<std::ffi::CString>`
+ found struct `std::vec::Vec<std::ffi::OsString>`