Unclear instructions in README how to build with stack

[vaclavsvejcar]

I'm trying to build brittany from master using stack, so I checked readme and it says to use:

stack install brittany # --resolver lts-16.31

which doesn't seem correct because obviously current version requires GHC 9.x. I also tried with latest nightly (nightly-2022-01-04) but it doesn't seem to fit as well:

Selected resolver: nightly-2022-01-04
Resolver 'nightly-2022-01-04' does not have all the packages to match your requirements.
    aeson version 1.5.6.0 found
        - brittany requires >=2.0.1 && <2.1
    butcher not found
        - brittany requires >=1.3.3 && <1.4
    data-tree-print not found
        - brittany requires >=0.1.0 && <0.2
    multistate not found
        - brittany requires >=0.8.0 && <0.9
    text version 1.2.4.1 found
        - brittany requires >=1.2.5 && <1.3
    Using package flags:
        - brittany: FlagName "pedantic" = False

Is actually brittany still intended to be built using any existing stack resolver? I know this is probably low priority stuff, but maybe it would be nice to have working stack.yaml to make it easier building brittany using stack, if possible?

[tfausak]

I changed the resolver at the suggestion of #361. Brittany isn't really intended to be installed with Stack. Some of its dependencies aren't on Stackage (butcher, data-tree-print, and multistate). Others are too old (aeson). Others are too new (text).

In theory this is solvable, but I don't have the bandwidth to support the build matrix necessary to build with all these dependencies.

Brittany could supply a stack.yaml to allow building it with Stack. That would only work for checking out the whole repo and building it with stack build. It wouldn't help at all with stack install brittany.

[vaclavsvejcar]

Just fyi, I was able to build brittany from master (0aa04af) using following stack.yaml:

resolver: nightly-2022-01-15

extra-package-dbs: []

flags: {}

packages:
  - "."

extra-deps:
  - butcher-1.3.3.2
  - data-tree-print-0.1.0.2
  - multistate-0.8.0.3
  - aeson-2.0.3.0
  - yaml-0.11.7.0

allow-newer: true

Given that brittany is command line tool and not library, maybe the range of supported GHC versions might not be such large and if only one major version will be supported (let's say only 9.0.x), maybe it might not be that difficult to put together some working stack.yaml to make it easier for folks willing to build brittany using Stack? If you'd be interested, I can try to help with this.