I think I'm -1 to run doctests as part of regrtest. Documentation examples are meant to be read, not executed: it is fine for them to omit unimportant information or trivial boilerplate (such as imports).

Any complication in the way doc examples must be written will deter us from actually writing examples.

Furthermore, spreading unit tests in the doc files instead of Lib/test files will make maintenance of tests more tedious as well.