Re: Using head.hackage

Note that this only happens with `aeson`, which is the package that the tutorial asks to add to `extra-packages` in 'cabal.project'. El mar., 10 sept. 2019 a las 19:17, Alejandro Serrano Mena (< trupill@gmail.com>) escribió:

The instructions are quite clear. Alas, when I try to reproduce the steps using my home-build compiler (for which I mean set the `with-compiler` in `cabal.project` to the stage2 compiler obtained by Hadrian), I get:

...

cabal new-install --lib aeson Distribution/Client/CmdInstall.hs:(361,18)-(363,72): Non-exhaustive patterns in lambda

Do you have any idea of what I might be doing wrong?

Thanks in advance, Alejandro

El mar., 10 sept. 2019 a las 12:32, Ben Gamari () escribió:

...

Alejandro Serrano Mena writes:

...

Dear GHC devs, As part of our work in "quick look impredicativity", we would like to test whether any package breaks. I've read about "head.hackage" as a way to test this fact, but I could not find any information.

Could somebody point me in the right direction? If it does not exist yet, I'll try to summarize whatever I learn in the wiki for future reference.

Hi Alejandro,

Indeed I have a pair of yet-to-be-published blog posts intended to discuss exactly this. See [1] and [2]. Do let me know if you have any questions.

Cheers,

- Ben

[1] https://gitlab.haskell.org/ghc/homepage/merge_requests/16/diffs [2] https://gitlab.haskell.org/ghc/homepage/merge_requests/29/diffs