Update Fedora repo in the install guide

[Iisus]

The Fedora Copr repo link was pointing to an obsolete repository, containing stack 1.9.3, so I've updated the link to point to the newer repo.

[Iisus]

Original pull request, #5250, was based on master. I've closed that one and opened this one, based on stable.
@snoyberg @juhp

[snoyberg]

Looks correct to me, @juhp can correct me if this needs to be reverted

[snoyberg]

Looks correct to me, @juhp can correct me if this needs to be reverted

[juhp]

Thank you @Iisus for this!

Sorry for taking so long to respond - I wasn't really slacking, but actually writing a small tool to do progressive copr builds... :-) and was also thinking about this issue, so sorry also for the long reply. ;o)

Just a few comments first anyway on Stack and Fedora:

First some good news: stack will be available as a package in Fedora 32 (actually subpackaged under haskell-platform - I still want to have it as a proper separate source Fedora package eventually of course - (also, too much detail, but to be accurate I think it will probably be shipped as a 0-day update to F32).

As for the coprs, the reason I made the separate (conservative) stack2 Copr repo was that when stack-2.1 was released initially there were some incompatibilities etc compared to the previous 1.9 release, so I wanted to have both versions available to users. But by now recent Stackage LTS major releases are no longer supported by 1.9, so I plan to build 2.1 soon in the stack copr (and keep a stack-1.9 copr in case anyone still needs it, eg on RHEL7). It seems a large new stack release is coming, and I may be tempted to put that first into a stack-2.4(?) copr initially because it will no longer support ghc7 (yeah I know ghc7 is getting old:)

So in conclusion probably the merged PR is fine for now, thanks, though stack2 doesn't have a build for epel7.

But in the longer term I may get rid of the stack2 repo, but we can revisit this before then: because the naming of the current two repos is actually confusing for users - I may well end up making a new stack-2.1 copr and then use the stack copr for the latest stable release (unfortunately copr doesn't support renaming of projects, so this will be a bit of extra work alas but nevermind). But more importantly going forward stack should be available as an official Fedora package for all archs (though I am not sure how many other Linux archs are supported upstream), though due to dependencies etc it may at times lag behind the latest upstream release of course specially for older Fedora and EPEL releases.