Danila Danko

Seems like this is a problem with `purix.buildSpagoLock`. I see a comment by @thomashoneyman [there](https://github.com/thomashoneyman/purescript-overlay/blame/4d9f42384efcfc934bbd818b05da3f3f50b5b991/nix/build-spago-lock.nix#L191-L205). But now there is `spago`. I don't get what's the problem with using it directly.

@f-f, building `spago` from source works (see https://github.com/thomashoneyman/purescript-overlay/pull/71). Tests fail so far. Should I move the code for bulding `spago` here?

@toastal, thank you for a review. I'm going to finish https://github.com/thomashoneyman/purescript-overlay/pull/71. When it works, I'll move the `spago` derivation from there to here.

@toastal, @thomashoneyman, the spago derivation works. However, I used the not yet merged PR https://github.com/thomashoneyman/purescript-overlay/pull/71. Could you please check both PRs? In this PR (to spago repo), you can run...

Hmm, what can be the error on macOS? UPD: it was due to longer than `devshell.menu.width` lines on macOS

@zimbatm, @blaggacao, please, review

@zimbatm, rebased.

There are some problems with types. I'll let you know when this PR is ready.

@zimbatm, this PR is ready for a review.

Okay, now, this PR is based #295 and #297