[Buildbot] #3554: should old-style step users rewrite their calls to addLog* addStd* when upgrading to buildbot9

[Buildbot trac]

#3554: should old-style step users rewrite their calls to addLog* addStd* when
upgrading to buildbot9
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Reporter:  yetanotherion    |      Owner:
    Type:  support-request  |     Status:  new
Priority:  major            |  Milestone:  undecided
 Version:  master           |   Keywords:
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 addLog*, addStd* are
 - synchronous in 8
 - asynchronous in 9
 The debate in new-style steps converged in the documentation:
 users should handle the deferred.

 Regarding old-style steps, the debate is however still open, and might
 generate discussions like in
 https://github.com/buildbot/buildbot/pull/2214

 Wrapping the synchronous API using asynchronous methods by means of
 deferred kung-fu, might have generated logical bombs in the code, which
 may make 9 harder to maintain.

 Instead of kung-fu ing further, this ticket aims at launching the debate
 on whether users
 - of old-style step
 - upgrading to buildbot9,

 Should be warned that:
 - upgrading to new-style step is necessary,
 - as instead they may experience bugs, quite hard to debug.

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Ticket URL: <http://trac.buildbot.net/ticket/3554>
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Buildbot: build/test automation