[GHC] #13614: Rewrite rules not applied exhaustively when simplifying from plugin

[GHC]

#13614: Rewrite rules not applied exhaustively when simplifying from plugin
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        Reporter:  nomeata           |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  GHC API           |              Version:  8.1
      Resolution:  worksforme        |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by nomeata):

 * status:  new => closed
 * resolution:   => worksforme


Comment:

 >  But I bet you have a non-debug compiler; and that you have an in-scope
 set that does not include foo. Might that be it?

 That seems to be it! (Although I had a hard time fixing it because of a
 bug(?) in the recompilation checker: If you used `-dynamic-too` before,
 but forget it later, GHC will happily use old
 `TestPlugin.dyn_o/TestPlugin.o` files, so I kept seeing unchanged
 behaviour… will file a bug).

 Incidentially, why is this not an issue for `simplifyExpr` in `SimplCore`
 – I don’t see code there adding anything to the in-scope set? Or is it ok
 because that function is not going to do such elaborate things as applying
 rules anyways?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13614#comment:4>
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