current stack fails to build with Cabal-3.4

[juhp]

General summary/comments (optional)

Can't build stack itself with ghc-9.0 (or Stackage Nightly).

Steps to reproduce

stack --resolver nightly build

(the next nightly after 2022-01-14 should contain pantry, since hackage-security and ed25519 got unlocked for ghc-9.0)

Actual

$ git diff
diff --git a/stack.yaml b/stack.yaml
index d1f4502f..12e65387 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -6,6 +6,8 @@ packages:
 extra-deps:
 - rio-0.1.21.0@rev:0
 - pantry-0.5.3@rev:0
+- hackage-security-0.6.0.1
+- ed25519-0.0.5.0
: 
$ stack --resolver nightly build
:
[ 62 of 111] Compiling Stack.Constants.Config [TH]
[ 74 of 111] Compiling Stack.Package

/var/home/petersen/haskell/stack/src/Stack/Package.hs:131:35: error:
    Not in scope: type constructor or class ‘D.Flag’
    Neither ‘Distribution.Package’, ‘Distribution.PackageDescription’,
            ‘Distribution.Text’,
            ‘Distribution.Verbosity’ nor ‘System.Directory’ exports ‘Flag’.
    |
131 |                               -> [D.Flag]
    |                                   ^^^^^^

/var/home/petersen/haskell/stack/src/Stack/Package.hs:938:13: error:
    Not in scope: type constructor or class ‘Flag’
    |
938 | flagMap :: [Flag] -> Map FlagName Bool
    |             ^^^^

/var/home/petersen/haskell/stack/src/Stack/Package.hs:940:17: error:
    Not in scope: type constructor or class ‘Flag’
    |
940 |   where pair :: Flag -> (FlagName, Bool)
    |                 ^^^^

/var/home/petersen/haskell/stack/src/Stack/Package.hs:989:21: error:
    Not in scope: data constructor ‘Flag’
    |
989 |                     Flag flag ->
    |                     ^^^^
Completed 166 action(s).

--  While building package stack-2.7.4 (scroll up to its section to see the error) using:
      /var/home/petersen/haskell/stack/.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.4.1.0/setup/setup --builddir=.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.4.1.0 build lib:stack exe:stack --ghc-options ""
    Process exited with code: ExitFailure 1

Stack version

$ stack --version
Version 2.7.3 x86_64
Compiled with:
- Cabal-3.2.1.0
:

Method of installation

• An unofficial package repository (please specify which): Fedora Linux

[Bodigrim]

For the reference, this is caused by changes in haskell/cabal#6725.

As a Hackage trustee, I made a revision https://hackage.haskell.org/package/stack-2.7.3/revisions/

[bergmark]

#5559

[mpilgrem]

I am closing this because it is fixed by #5696.