How to get the BDD-style output?

I am probably missing the obvious, but I tried the tutorial BDD example and the output I get is

```
===============================================================================
All tests passed (16 assertions in 1 test case)
```

Instead of the described:

```
Scenario: vectors can be sized and resized
Given: A vector with some items
When: more capacity is reserved
Then: the capacity changes but not the size
```

How should I get the expected output? Should I pass a specific option to the program?
I tried -s, but still it does not look like that at all.

Start with the tutorial BDD example and the command-line -s option mentioned in the issue. Compare the documented output with the current program output and determine whether the invocation or the tutorial needs clarification. Done means the expected way to obtain BDD-style output is clearly documented.

Written by the indexing model from the issue text.