[WIP] chore(docs): update lts version and fix nightly link

[mohoff]

Few things I noticed and partially addressed while getting started with the Guide:

• updated resolver version to latest lts.
• fixed nightly link (/nightly doesn't resolve)

Under heading Stack's functions, I'd would be nice to have a short paragraph on:

• how Stack relates to Cabal and other relevant tooling
• what Stack does not attempt to solve

Also, two issues I would need your input on:

1. The guide mentions --solver under section External Dependencies. This flag doesn't exist anymore and seems to be replaced by --resolver <arg> which needs an argument. How to update this part?

2. Following (1), I tried to run stack install caball-install anyway. It errors with a version conflict:

   In the dependencies for cabal-install-3.0.0.0:
   base-4.13.0.0 from stack configuration does not
                 match >=4.8 && <4.13  (latest matching version
                 is 4.12.0.0)
   hackage-security must match >=0.5.2.2 && <0.6, but the stack
                    configuration has no specified version  (latest
                    matching version is 0.5.3.0)
   needed since cabal-install is a build target.
   

   How to handle this in the Guide?

[mattaudesse]

Thanks for taking the effort to file this @mohoff.

Unfortunately I think you've bumped into a few things which are in a state of flux at the moment, so I'm sure following the guide was more confusing than we'd like it to be.

I've made a few notes that'll hopefully help.

---

2. Following (1), I tried to run stack install caball-install anyway. It errors with a version conflict:

In the dependencies for cabal-install-3.0.0.0:
base-4.13.0.0 from stack configuration does not
             match >=4.8 && <4.13  (latest matching version
             is 4.12.0.0)
hackage-security must match >=0.5.2.2 && <0.6, but the stack
                configuration has no specified version  (latest
                matching version is 0.5.3.0)
needed since cabal-install is a build target.

Another good catch, but thankfully I think this is a temporary glitch as stack + stackage catch up with the new ghc + cabal internals. For now, using LTS 14.27 instead seems to work alright for me if you'd like to try that:

$ stack --resolver lts-14.27 install cabal-install

Somewhat related: https://tech.fpcomplete.com/blog/base-on-stackage

[mattaudesse]

It definitely takes a moment or two before I receive a result, but the old URI works for me:

$ curl --head https://www.stackage.org/nightly
HTTP/2 303 
server: nginx/1.15.9
date: Sun, 15 Mar 2020 19:02:10 GMT
content-type: text/plain; charset=utf-8
content-length: 0
cache-control: no-cache, must-revalidate
expires: Thu, 01 Jan 1970 05:05:05 GMT
location: /nightly-2020-03-14 # <--- *** note the location header ***
vary: Accept, Accept-Language
x-xss-protection: 1; mode=block
strict-transport-security: max-age=15724800; includeSubDomains

Does that not work when you try?

[mohoff]

true - guess I was too impatient :)

[mattaudesse]

The guide mentions --solver under section External Dependencies. This flag doesn't exist anymore and seems to be replaced by --resolver which needs an argument. How to update this part?

Good catch - stack dropped its --solver support awhile back, so you've spotted some stale docs.

I know others (e.g. here) have noticed the discrepancy and there's been some talk about updating the docs but without digging too far I'm unsure what the status is.

If you look at the stack.yaml that stack new gives you by default, it lists an extra-deps stanza that shows how one would normally add acme-missiles in practice now.

[mohoff]

Thanks for the replies and provided background @mattaudesse , and, sorry for my late response.

Closing this MR seems reasonable then. Happy to contribute when things stabilized more and when I have a better understanding of how things are connected.