v1 style warnings during stack ./install.hs

[nponeccop]

Warning: The update command is a part of the legacy v1 style of cabal usage. and I think a few different ones later.

[samuelpilz]

I think this is because cabal-helper does not yet work with cabal new-build. Running cabal (v1-)update is necessary for it to work. Hopefully, after #1168, only one such error appears.

When the hie-bios replaces cabal-helper, it will bring a lot more sanity to this project 🎉

[samuelpilz]

#1126

[nponeccop]

I didn't mean to move to new-build. I only meant to replace update with v1-update to suppress the warning.

AFAIK new-build doesn't work on Windows at all yet so it's impossible to move to it.

[samuelpilz]

I can do that