Ugly highlighting of substituted unicode in HEAD
I am currently seeing the following:

This is the default colour scheme, but it happens in any I choose. I'm not sure what's happened here, but I certainly liked how it was before, with no background colour on substitutions :)
git bisect on vim2hs points to 6646a392c68bdb9f9744b876f68366a39a60265f as the offending commit.
Ah, yeah. The problem here is most colorschemes including Vim's default doesn't have a pretty style for the Conceal highlight group, which is why I had been overriding it in vim2hs (even though it should be up to the colorscheme and other types of plugins shouldn't touch it), but changing it to use highlight default means it doesn't force the override anymore.
The offending line is highlight default link Conceal Operator in conceal.vim; pull request?
Pull request for what? Reverting the line to its previous state or something more elaborate? I just updated vim2hs and stumbled upon this too.
Hi, is there a workaround for this yet? Because I already tried a dozen color schemes and still no luck.
Adding hi clear Conceal at the end of .vimrc fixes it.