Strange bug with "UnboxedTuples"

[nrolland]

When this extension is enabled, I can't evaluate expressions

{-# LANGUAGE UnboxedTuples #-}

module SOQuestionRLSBug where

-- >>> show 3 -- disable "UnboxedTuples" to evaluate this expression in RLS from Visual studio

[pepeiborra]

This happens because GHC doesn't support UnboxedTuples in bytecode, which is what the eval plugin uses.
Could you try to use {-# OPTIONS -fobject-code #-} and report back?

[July541]

Adding {-# OPTIONS -fobject-code #-} seems not work.
Combining the Dynflag Opt_ByteCodeIfUnboxed with the ghcSession can prevent this bug happen. Maybe we can add an extra Opt_ByteCodeIfUnboxed flag if the module is not interpreted, but I am not sure is it a generalized solution.

[jneira]

• Related with Unboxed tuple error when importing a module with no-specialise #771

[michaelpj]

This should work in newer GHCs, so I think we can close this