Bug#1012568: haskell_devscripts: package registration needs to be run with UTF-8 locale

[Scott Talbert]

Package: haskell-devscripts
Severity: important

haskell_devscripts needs to run GHC registration with a UTF-8 locale.
Otherwise, it will fail with an error like the below if the .cabal file
contains a UTF-8 copyright symbol:

Running debian/hlibrary.setup register --builddir=dist-ghc --gen-pkg-config --verbose=verbose+nowrap
Non-zero exit code 1.
/usr/bin/ghc --abi-hash -fbuilding-cabal-package -O -outputdir dist-ghc/build -odir dist-ghc/build -hidir dist-ghc/build -stubdir dist-ghc/build -i -idist-ghc/build -isrc -idist-ghc/build/autogen -idist-ghc/build/global-autogen -Idist-ghc/build/autogen -Idist-ghc/build/global-autogen -Idist-ghc/build -optP-include -optPdist-ghc/build/autogen/cabal_macros.h -this-unit-id hslua-module-text-0.2.1-KVQIhWqJT8R8zGxab7jo31 -hide-all-packages -Wmissing-home-modules -no-user-package-db -XHaskell2010 Foreign.Lua.Module.Text -optl-Wl,-z,relro
name:                 hslua-module-text
version:              0.2.1
visibility:           public
id:                   hslua-module-text-0.2.1-KVQIhWqJT8R8zGxab7jo31
key:                  hslua-module-text-0.2.1-KVQIhWqJT8R8zGxab7jo31
license:              MIT
copyright:            <stdout>: commitBuffer: invalid argument (invalid character)
make: *** [/usr/share/cdbs/1/class/hlibrary.mk:172: install/libghc-hslua-module-text-dev] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2

This used to be done in Dh_Haskell.sh in 0.16.2 [1], but was lost in the
recent perl changes.

@Felix - any advice on how to fix this?  It seems the LC_ALL=C.UTF-8
can't be prepended to the command line as was before as bash isn't used.

[1] https://salsa.debian.org/haskell-team/haskell-devscripts/-/blob/debian/0.16.2/Dh_Haskell.sh#L605