#### 10.2.5 fail

If a test fails, it is usually because one of the `docommand` calls fails, and so direct calls to the `fail` function are rare. However, if you do want to call this function directly, you should supply as its argument a short description of what has gone wrong. For example, the `docommand` function uses `fail` in the following way:-

    fail "$label: $1: Expected return value $2, got return value $rv"