There is an updated pull request by chexum against master on the void-packages repository

https://github.com/chexum/void-packages ghc-884
https://github.com/void-linux/void-packages/pull/31898

ghc: allow building with current Sphinx
./srcpkg build ghc fails with current tools:

"inplace/bin/ghc-stage1" [...] /build/cbits/longlong.p_o
Running Sphinx v4.0.2

Configuration error:
There is a syntax error in your configuration file: (unicode error) 'unicodeescape' codec can't decode bytes in position 1-2: truncated \uXXXX escape (conf.py, line 87)

...
make: *** [Makefile:128: all] Error 2

According to https://gitlab.haskell.org/ghc/ghc/-/issues/19962

>> This fix is to use raw strings, as already done in master:
>> https://gitlab.haskell.org/ghc/ghc/-/blob/master/docs/users_guide/conf.py#L96

Sanitized from commit (only small parts apply)
https://gitlab.haskell.org/ghc/ghc/-/commit/83407ffc7acc00cc025b9f6ed063add9ab9f9bcc

#### General
- [ ] This is a new package and it conforms to the [quality requirements](https://github.com/void-linux/void-packages/blob/master/Manual.md#quality-requirements)

#### Have the results of the proposed changes been tested?
- [ ] I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
- [x] I generally don't use the affected packages but briefly tested this PR

[skip CI] build might take over 3 hours with a single CPU - local build/pkg tested

#### Does it build and run successfully? 
(Please choose at least one native build and, if supported, at least one cross build. More are better.)
- [x] I built this PR locally for my native architecture, (x86_64)
- [ ] I built this PR locally for these architectures (if supported. mark crossbuilds):
  - [ ] aarch64-musl
  - [ ] armv7l
  - [ ] armv6l-musl


A patch file from https://github.com/void-linux/void-packages/pull/31898.patch is attached