There are some issues where I haven't tracked down the cause. It seems to be that mozrepl sends more output than expected in some situations. There is discussion on the bugtracker, and a likely approach will be to write what mozrepl calls a "custom interactor".

In reply to Re: WWW::Mechanize::Firefox malformed JSON error? by Corion
in thread WWW::Mechanize::Firefox malformed JSON error? by tcordes

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