Imported constraint edit not seen by cabal build

[philderbeast]

I've noticed a change in behaviour of cabal-install between cabal-install-3.10.3.0 and the version built from HEAD.

I'm having a go at converting hledger to use Updo for project generation. Like many such conversions, when there's a dependency on a version of a package that conflicts with a version on stackage, the stackage provided cabal.config must then be downloaded to project-stackage/lts-m.n.config (depending on the resolver) and edited locally to remove the conflicts, see maintaining a project. This cabal.config from stackage is imported into the cabal.project.

project-stackage
└── lts-m.n.config  # actually ./project-stackage/lts-18.28.config in this case

The change in behaviour I'm observing is that I could make these edits and rerun make -f project-files.mk cabal.project and the edit would be picked up immediately with cabal-install-3.10.3.0 but with cabal-install built from HEAD, the edit is not picked up. I can force it to be picked up by issuing a cabal clean.

Excuse me for not providing a more minimal reproduction right away but it is what I have at hand and this change in behaviour slows down the edit build turnaround speed for Updo conversion, from build-edit-build to build-edit-clean-build is more steps and slower. I could see it causing confusion too if a cabal-install user is left to wonder why an edit is not being picked up immediately.

• With cabal-3.10.3.0

$ ~/.ghcup/bin/cabal --version
cabal-install version 3.10.3.0
compiled using version 3.10.3.0 of the Cabal library

$ ~/.ghcup/bin/cabal build all --enable-tests --enable-benchmarks
...
Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] next goal: hledger-lib (user goal)
[__0] rejecting: hledger-lib-1.33.99 (constraint from project config
./project-stackage/lts-18.28.config requires ==1.21)
[__0] rejecting: hledger-lib-1.33.1, hledger-lib-1.33, hledger-lib-1.32.3,
hledger-lib-1.32.2, hledger-lib-1.32.1, hledger-lib-1.32, hledger-lib-1.31,
hledger-lib-1.30, hledger-lib-1.29.2, hledger-lib-1.29.1, hledger-lib-1.29,
hledger-lib-1.28, hledger-lib-1.27.1, hledger-lib-1.27, hledger-lib-1.26.1,
hledger-lib-1.26, hledger-lib-1.25, hledger-lib-1.24.1, hledger-lib-1.24,
hledger-lib-1.23, hledger-lib-1.22.2, hledger-lib-1.22.1, hledger-lib-1.22,
hledger-lib-1.21, hledger-lib-1.20.4, hledger-lib-1.20.3, hledger-lib-1.20.2,
hledger-lib-1.20.1, hledger-lib-1.20, hledger-lib-1.19.1, hledger-lib-1.19,
hledger-lib-1.18.1, hledger-lib-1.18, hledger-lib-1.17.1,
hledger-lib-1.17.0.1, hledger-lib-1.17, hledger-lib-1.16.2,
hledger-lib-1.16.1, hledger-lib-1.16, hledger-lib-1.15.2, hledger-lib-1.15.1,
hledger-lib-1.15, hledger-lib-1.14.1, hledger-lib-1.14, hledger-lib-1.13.1,
hledger-lib-1.13, hledger-lib-1.12, hledger-lib-1.11.1, hledger-lib-1.11,
hledger-lib-1.10, hledger-lib-1.9.1, hledger-lib-1.9, hledger-lib-1.5.1,
hledger-lib-1.5, hledger-lib-1.4, hledger-lib-1.3.2, hledger-lib-1.3.1,
hledger-lib-1.3, hledger-lib-1.2, hledger-lib-1.1, hledger-lib-1.0.1,
hledger-lib-1.0, hledger-lib-0.27.1, hledger-lib-0.27, hledger-lib-0.26,
hledger-lib-0.25.1, hledger-lib-0.25, hledger-lib-0.24.1, hledger-lib-0.24,
hledger-lib-0.23.3, hledger-lib-0.23.2, hledger-lib-0.23.1, hledger-lib-0.23,
hledger-lib-0.22.2, hledger-lib-0.22.1, hledger-lib-0.22, hledger-lib-0.21.3,
hledger-lib-0.21.2, hledger-lib-0.21.1, hledger-lib-0.21,
hledger-lib-0.20.0.1, hledger-lib-0.20, hledger-lib-0.19.3,
hledger-lib-0.19.1, hledger-lib-0.19, hledger-lib-0.18.2, hledger-lib-0.18.1,
hledger-lib-0.18, hledger-lib-0.17, hledger-lib-0.16.1, hledger-lib-0.16,
hledger-lib-0.15.2, hledger-lib-0.15, hledger-lib-0.14, hledger-lib-0.13,
hledger-lib-0.12.1, hledger-lib-0.12, hledger-lib-0.11.1, hledger-lib-0.11,
hledger-lib-0.10, hledger-lib-0.9, hledger-lib-1.24.99 (constraint from user
target requires ==1.33.99)
[__0] fail (backjumping, conflict set: hledger-lib)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: hledger-lib

Make the edit, commenting out the line in the downloaded cabal.config (in ./project-stackage/lts-18.28.config) for hledger-lib ==1.21, and then try again we get the next conflict right away:

constraints:
...
-              hledger-lib ==1.21,
+           -- hledger-lib ==1.21,

$ ~/.ghcup/bin/cabal build all --enable-tests --enable-benchmarks
Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] trying: hledger-lib-1.33.99 (user goal)
[__1] next goal: terminal-size (dependency of hledger-lib)
[__1] rejecting: terminal-size-0.3.4 (constraint from project config
./project-stackage/lts-18.28.config requires ==0.3.2.1)
[__1] rejecting: terminal-size-0.3.3, terminal-size-0.3.2.1,
terminal-size-0.3.2, terminal-size-0.3.1, terminal-size-0.3.0,
terminal-size-0.2.1.0, terminal-size-0.2.0.0, terminal-size-0.1.0.0
(constraint from project config
/home/philderbeast/dev/src/updo/hledger/cabal.project requires ==0.3.4)
[__1] fail (backjumping, conflict set: hledger-lib, terminal-size)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: hledger-lib, terminal-size

• With cabal-HEAD

$ git rev-parse HEAD
b7ed4f76e0b3d7a33b58ee3a3691128199a196c1

$ cabal install cabal-install:exe:cabal --overwrite-policy=always

$ cabal --version
cabal-install version 3.13.0.0
compiled using version 3.13.0.0 of the Cabal library

$ cabal build all --enable-tests --enable-benchmarks
Warning: this is a debug build of cabal-install with assertions enabled.
Resolving dependencies...
Error: [Cabal-7107]
Could not resolve dependencies:
[__0] next goal: hledger-lib (user goal)
[__0] rejecting: hledger-lib-1.33.99
      (constraint from project-stackage/lts-18.28.config requires ==1.21)
        imported by: cabal.project
[__0] rejecting: hledger-lib; 1.33.1, 1.33, 1.32.3, 1.32.2, 1.32.1, 1.32, 1.31, 1.30, 1.29.2, 1.29.1, 1.29, 1.28, 1.27.1, 1.27, 1.26.1, 1.26, 1.25, 1.24.1, 1.24, 1.23, 1.22.2, 1.22.1, 1.22, 1.21, 1.20.4, 1.20.3, 1.20.2, 1.20.1, 1.20, 1.19.1, 1.19, 1.18.1, 1.18, 1.17.1, 1.17.0.1, 1.17, 1.16.2, 1.16.1, 1.16, 1.15.2, 1.15.1, 1.15, 1.14.1, 1.14, 1.13.1, 1.13, 1.12, 1.11.1, 1.11, 1.10, 1.9.1, 1.9, 1.5.1, 1.5, 1.4, 1.3.2, 1.3.1, 1.3, 1.2, 1.1, 1.0.1, 1.0, 0.27.1, 0.27, 0.26, 0.25.1, 0.25, 0.24.1, 0.24, 0.23.3, 0.23.2, 0.23.1, 0.23, 0.22.2, 0.22.1, 0.22, 0.21.3, 0.21.2, 0.21.1, 0.21, 0.20.0.1, 0.20, 0.19.3, 0.19.1, 0.19, 0.18.2, 0.18.1, 0.18, 0.17, 0.16.1, 0.16, 0.15.2, 0.15, 0.14, 0.13, 0.12.1, 0.12, 0.11.1, 0.11, 0.10, 0.9, 1.24.99 (constraint from user target requires ==1.33.99)
[__0] fail (backjumping, conflict set: hledger-lib)
After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: hledger-lib

Make edit and try again but no change (same output as above). The next conflict is shown only after a clean:

$ cabal build all --enable-tests --enable-benchmarks
Warning: this is a debug build of cabal-install with assertions enabled.
Resolving dependencies...
Error: [Cabal-7107]
Could not resolve dependencies:
[__0] next goal: hledger-lib (user goal)
[__0] rejecting: hledger-lib-1.33.99
      (constraint from project-stackage/lts-18.28.config requires ==1.21)
        imported by: cabal.project
[__0] rejecting: hledger-lib; 1.33.1, 1.33, 1.32.3, 1.32.2, 1.32.1, 1.32, 1.31, 1.30, 1.29.2, 1.29.1, 1.29, 1.28, 1.27.1, 1.27, 1.26.1, 1.26, 1.25, 1.24.1, 1.24, 1.23, 1.22.2, 1.22.1, 1.22, 1.21, 1.20.4, 1.20.3, 1.20.2, 1.20.1, 1.20, 1.19.1, 1.19, 1.18.1, 1.18, 1.17.1, 1.17.0.1, 1.17, 1.16.2, 1.16.1, 1.16, 1.15.2, 1.15.1, 1.15, 1.14.1, 1.14, 1.13.1, 1.13, 1.12, 1.11.1, 1.11, 1.10, 1.9.1, 1.9, 1.5.1, 1.5, 1.4, 1.3.2, 1.3.1, 1.3, 1.2, 1.1, 1.0.1, 1.0, 0.27.1, 0.27, 0.26, 0.25.1, 0.25, 0.24.1, 0.24, 0.23.3, 0.23.2, 0.23.1, 0.23, 0.22.2, 0.22.1, 0.22, 0.21.3, 0.21.2, 0.21.1, 0.21, 0.20.0.1, 0.20, 0.19.3, 0.19.1, 0.19, 0.18.2, 0.18.1, 0.18, 0.17, 0.16.1, 0.16, 0.15.2, 0.15, 0.14, 0.13, 0.12.1, 0.12, 0.11.1, 0.11, 0.10, 0.9, 1.24.99 (constraint from user target requires ==1.33.99)
[__0] fail (backjumping, conflict set: hledger-lib)
After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: hledger-lib

$ cabal clean
Warning: this is a debug build of cabal-install with assertions enabled.

$ cabal build all --enable-tests --enable-benchmarks
Warning: this is a debug build of cabal-install with assertions enabled.
Resolving dependencies...
Error: [Cabal-7107]
Could not resolve dependencies:
[__0] trying: hledger-lib-1.33.99 (user goal)
[__1] next goal: terminal-size (dependency of hledger-lib)
[__1] rejecting: terminal-size-0.3.4
      (constraint from project-stackage/lts-18.28.config requires ==0.3.2.1)
        imported by: cabal.project
[__1] rejecting: terminal-size; 0.3.3, 0.3.2.1, 0.3.2, 0.3.1, 0.3.0, 0.2.1.0, 0.2.0.0, 0.1.0.0
      (constraint from cabal.project requires ==0.3.4)
[__1] fail (backjumping, conflict set: hledger-lib, terminal-size)
After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: hledger-lib, terminal-size

Is this an intended change in behaviour in the upcoming cabal-install release?

[philderbeast]

I did a git bisect and found that this change arrived with #9578.