Django: Displaying formset errors correctly

I have an inline formset for a model, which has a unique_together constraint. And so, when I input data, which doesn't fulfill this constraint, it displays:

__all__Please correct the duplicate values below.

The code, which does this is:

    {% for error in formset.errors %}
        {{ error }}<br/>
    {% endfor %}

I don't much like the __all__ at the beginning of the error and it is quite clearly the dictionary key, so I tried:

    {% for key, error in formset.errors %}
        {{ key }}: {{ error }}<br/>
    {% endfor %}

But then all I get is:

__all__:

{{ error }} won't display at all. So what's going on here? And how do I display the error correctly?