Comment 2 for bug 234120

Ah. I think I know what's happening here: it's pydoctor's hackish way of extracting a summary line. For the table of contents, pydoctor takes the first non-blank line of ths docstring. In this case it's just "B{foo", which is unsurprisingly an error. It works fine for formatting the main docstring.

Not sure what to do about this.