Build fails on FreeBSD-12.0 ghc-8.6.3

[mmzx]

This PR fixes a fatal build issue. To reproduce:

cabal new-build results with the following:
Resolving dependencies...
Build profile: -w ghc-8.6.3 -O1
In order, the following will be built (use -v for more details):

• vector-th-unbox-0.2.1.6 (lib) (first run)
  Configuring library for vector-th-unbox-0.2.1.6..
  Preprocessing library for vector-th-unbox-0.2.1.6..
  Building library for vector-th-unbox-0.2.1.6..
  ghc: fd:16: hGetContents: invalid argument (invalid byte sequence)

Data/Vector/Unboxed/Deriving.hs:18:21: error:
warning: treating Unicode character <U+2212> as identifier character rather than as '-' symbol [-Wunicode-homoglyph]
|
18 | Copyright: ? 2012?2015 Liyang HU
| ^
cc' failed in phase C pre-processor'. (Exit code: -13)

[phadej]

Newer cabal-install reads .cabal files as binary. I don't think this issue is reproducible with cabal-install-2.4.1.0 or 3.0.0.0

[mmzx]

Newer cabal-install reads .cabal files as binary. I don't think this issue is reproducible with cabal-install-2.4.1.0 or 3.0.0.0

Right. In those circumstances, it compiles. However, some systems still use cabal-install-2.4.0.x and newer cabal isn't accessible from package repositories.

Would updating the version of the cabal file cause the compilation to fail gracefully? :)

[mmzx]

@phadej , Have you maybe received the email by any chance that I have addressed to @liyang ? - just thinking maybe it was forwarded towards you.

[phadej]

@mmzx

• in Ghc 8.8.1 #23 i also made .cabal file ASCII, so it would fix the issue when merged
• No I haven't received any mails, I actually sent an email myself to Liyang partly as a Hackage Trustee to follow the NMU policy. I hope Liyang would reply some of us, so trustees don't need to step in.

[mmzx]

Coincident, I had emailed him on the day of your update in this conversation; thinking that @phadej may actually be a Hackage Trustee member. Great! :)