Dhall-haskell: Tighten base bounds on latest Dhall (1.38.0)

[vmchale]

Has a silly little error with GHC 8.4.4:

Failed to build dhall-1.38.0.
Build log (
/home/vanessa/.cabal/logs/ghc-8.4.4/dhall-1.38.0-5f6c290ce61d2413104cf7b27d787d394acc9f059b32d25462e4185ed5f1af3c.log
):
Configuring library for dhall-1.38.0..
Preprocessing library for dhall-1.38.0..
Building library for dhall-1.38.0..

src/Dhall/Syntax.hs:7:14: error:
    Unsupported extension: GeneralisedNewtypeDeriving
    Perhaps you meant ‘GeneralizedNewtypeDeriving’ or ‘NoGeneralizedNewtypeDeriving’
  |
7 | {-# LANGUAGE GeneralisedNewtypeDeriving #-}
  |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
cabal: Failed to build dhall-1.38.0 (which is required by
test:shake-dhall-test from shake-dhall-0.1.1.3). See the build log above for
details.

[Gabriel439]

@vmchale: Alternatively, could we fix it to use GeneralizedNewtypeDeriving (with a z)?

[Gabriel439]

Fix is up here: https://github.com/dhall-lang/dhall-haskell/pull/2143

[vmchale]

Nice!

dhall-1.38.0 needs a revision still, right?

1.38.1 could support GHC 8.4.4 ^

[Gabriel439]

@vmchale: I just pushed a revision to amend the lower bound on base to 4.12.0.0

[vmchale]

Thanks!