Remove some ByteString Assumptions

[nikivazou]

Trying to fix the build error:

/private/var/folders/2f/kzm4yd19613d13hyqzgtrd7h0000gp/T/stack-e0a2d75deeabe009/liquidhaskell-0.9.2.5.0/src/Data/ByteString_LHAssumptions.hs:15:8: error:
liquidhaskell>     • Unknown variable `Data.ByteString.Internal.empty`
liquidhaskell>     Var
liquidhaskell>     •
liquidhaskell>    |
liquidhaskell> 15 | assume Data.ByteString.Internal.empty :: { bs : Data.ByteString.ByteString | bslen bs == 0 }

[facundominguez]

Hello @nikivazou. Do you have a way to reproduce this failure? CI was green before and after this change. Maybe we should contribute a regression test.

[nikivazou]

Hmmm, not sure how to add a regression test for this... My stack.yaml and cabal files were the below, if it is of any help. I assume something changed in the Data.ByteString.Internal library?

resolver:
  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/26.yaml

packages:
- .

extra-deps:
  - hashable-1.3.5.0
  - smtlib-backends-0.3
  - smtlib-backends-process-0.3
  - rest-rewrite-0.4.0
  - git: https://github.com/ucsd-progsys/liquidhaskell.git
    commit: bc945637bb30cdeca38f52a2c86ba36a5d702bff
    subdirs:
      - .
      - liquidhaskell-boot
  - git: https://github.com/ucsd-progsys/liquid-fixpoint.git
    commit: 1ccf4b3962b4c3a3f4c17537280ec70edfa85c3e
allow-newer: true

  build-depends:       base >=4.16 && <4.17, containers, liquidhaskell
  hs-source-dirs:      src
  default-language:    Haskell2010
  ghc-options:         -fplugin=LiquidHaskell