What is the behaviour you would want/expect when 'Checkpage' is enabled?

A simple boolean value - if the arg is used, read checkpage - if 'true', continue script - if false, stop and exit script.

I know some of the scripts have a "enablePage" - but a lot of them don't.

That doesn't tell me anything about what it should do. What is 'checkpage'? What should the bot do with it? When? What should it do in which case?

Exactly what the '-enable:' parameter does in lonelypages.py - http://svn.wikimedia.org/svnroot/pywikipedia/trunk/pywikipedia/lonelypages.py

This behavior is not the same as blocking a bot by admins; it only prohibits the next start of the bot. So I am not sure if this is what you want to.

True, it is different then an admin stopping the bot via blocking, which of course would be instant. I was thinking more of implementations on cron - allowing any user to 'disable' the next run of a cronjob'd script until the BotOp is online/able to address a problem that may have arisen.

\(Alternatively, one could rewrite the -enable option to be checked every 10-25 pages, and so stop a bot from running even in 'mid-script'.\)

reflinks.py also implements a similar system ('stopPage'). It checks the latest revid (not the content), but every 20 edits.

Change 137980 had a related patch set uploaded by Ricordisamoa:
PROOF-OF-CONCEPT: check own talk, a custom page, and notifications

https://gerrit.wikimedia.org/r/137980

no code to review yet

Change 137980 had a related patch set uploaded (by Ricordisamoa):
PROOF-OF-CONCEPT: check own talk, a custom page, and notifications

https://gerrit.wikimedia.org/r/137980

Change 137980 abandoned by Ricordisamoa:
PROOF-OF-CONCEPT: check own talk, a custom page, and notifications

Reason:
John Vandenberg

https://gerrit.wikimedia.org/r/137980

I think the best approach would be the one from reflinks:

stop_page = "User talk:MyBot"

stop_page = "User talk:" + username

stop_page_rev_id = stop_page.latest_revision_id

...

if editedpages % 20 == 0:
    actual_rev = stop_page.latest_revision_id
    if actual_rev != stop_page_rev_id:
        pywikibot.output('Bot was interrupted by stop page!')
        return

-stoppage:"User:MyBot/Different Stop Page For This Job"

Oops.