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GHCi should not defer typed holes

    • Closed Issue created by Thomas Miedema @thomie

    In the function tcUserStmt in compiler/typecheck/TcRnDriver.hs, before going over the different ways ('plans') to lift an expression typed at the prompt into the GHCi monad, Opt_DeferTypeErrors is disabled. Here is the accompanying comment:

             -- Ensure that type errors don't get deferred when type checking the
         -- naked expression. Deferring type errors here is unhelpful because the
         -- expression gets evaluated right away anyway. It also would potentially
         -- emit redundant type-error warnings, one from each plan.
         ; plan <- unsetGOptM Opt_DeferTypeErrors $

    Since Opt_DeferTypeErrors implies Opt_DeferTypedHoles, Opt_DeferTypedHoles should be disabled here as well. This will improve the error message for T10248.

    Trac metadata
    Trac field Value
    Version 7.10.2
    Type Bug
    TypeOfFailure OtherFailure
    Priority normal
    Resolution Unresolved
    Component GHCi
    Test case
    Differential revisions
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    Blocking
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    Operating system
    Architecture
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