> # Branch (depth 0)
> cat_line(branch0)
Error: foo
Execution halted

> # Full
> cat_line(full0)
Error: foo
Execution halted

> # Branch (depth 1)
> cat_line(branch1)
Error: foo
Backtrace:
 1. global::f()
Execution halted

> # Full (depth 1)
> cat_line(full1)
Error: foo
Backtrace:
    x
 1. \-global::f()
Execution halted

