[MacPorts] #38862: Automatically clean builds with old statefile formats

[MacPorts]

#38862: Automatically clean builds with old statefile formats
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  Reporter:  ryandesign@…  |      Owner:  macports-tickets@…
      Type:  enhancement   |     Status:  new
  Priority:  Normal        |  Milestone:
 Component:  base          |    Version:  2.1.3
Resolution:                |   Keywords:
      Port:                |
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Comment (by cal@…):

 Replying to [ticket:38862 ryandesign@…]:
 > I would actually be in favor of doing exactly that starting with
 MacPorts 2.2. It's probably best if any builds started with MacPorts 2.1.x
 or earlier are automatically blown away and restarted, given the several
 changes that have gone into trunk that affect many ports (change in
 default compilers (r102269); change in default optimization level
 (#38218); change in library header padding (#29838); no more library
 overlinking (#38010)). Since statefile version 2 appeared in MacPorts
 2.1.3, I'd like to increase the statefile version to 3 before the release
 of MacPorts 2.2.

 We can think about that, but we will get the same problem we had when
 switching from statefile format 2 to 3 – we can't just blow away all
 partial builds with an older statefile format, because afaik it would
 break the binary archives and re-activating previously deactivated ports.

 > comment:ticket:29223:68 cites a problem with this idea, something about
 binary archives containing a statefile and therefore not being used if we
 were to make this change? This refers to the "+STATE" file I think? I
 guess I don't understand why that file is part of our archives or why
 MacPorts checks its contents.

 From what I understood (and I haven't actually checked the code for that)
 the binary archives work by shipping a statefile and MacPorts picks up
 after the last action the statefile lists as done. I'll need to have a
 look at the relevant base code for this case, but if it was easy to drop
 support for the old statefile format I'd have done it.

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Ticket URL: <https://trac.macports.org/ticket/38862#comment:1>
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