Backport #10507: Print out which project file we're using by default (fix #8519)

[mergify]

Attempting to resurrect #8617

---

Template Α: This PR modifies behaviour or interface

Include the following checklist in your PR:

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

---

This is an automatic backport of pull request #10507 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of a6082fc has failed:

On branch mergify/bp/3.14/pr-10507
Your branch is up to date with 'origin/3.14'.

You are currently cherry-picking commit a6082fcb5.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   cabal-install/src/Distribution/Client/ProjectPlanning.hs
	modified:   cabal-testsuite/PackageTests/Backpack/Includes2/cabal-external-target.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes2/cabal-external.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes2/cabal-internal-target.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes2/cabal-internal.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes2/cov.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes3/cabal-external.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes3/cabal-internal.out
	modified:   cabal-testsuite/PackageTests/Backpack/Includes3/cabal-repo.out
	modified:   cabal-testsuite/PackageTests/Backpack/Reexport2/cabal.out
	modified:   cabal-testsuite/PackageTests/Backpack/T6385/cabal.out
	modified:   cabal-testsuite/PackageTests/Backpack/bkpcabal01/cabal.out
	modified:   cabal-testsuite/PackageTests/BuildAutogenPackageGuard/cabal.out
	modified:   cabal-testsuite/PackageTests/BuildDeps/DepCycle/cabal.out
	modified:   cabal-testsuite/PackageTests/BuildDeps/InternalLibrary1/cabal.out
	modified:   cabal-testsuite/PackageTests/BuildTargets/UseLocalPackage/use-local-version-of-package.out
	modified:   cabal-testsuite/PackageTests/BuildTargets/UseLocalPackageForSetup/use-local-package-as-setup-dep.out
	modified:   cabal-testsuite/PackageTests/BuildToolDepends/setup.out
	modified:   cabal-testsuite/PackageTests/BuildTools/External/cabal.out
	modified:   cabal-testsuite/PackageTests/BuildTools/Internal/cabal.out
	modified:   cabal-testsuite/PackageTests/CmmSources/cabal.out
	modified:   cabal-testsuite/PackageTests/CmmSourcesDyn/cabal.out
	modified:   cabal-testsuite/PackageTests/CmmSourcesExe/cabal.out
	modified:   cabal-testsuite/PackageTests/ConditionalAndImport/cabal.out
	modified:   cabal-testsuite/PackageTests/ConditionalAndImport/cabal.test.hs
	modified:   cabal-testsuite/PackageTests/ConfigFile/T8487/cabal.out
	modified:   cabal-testsuite/PackageTests/Configure/cabal.out
	modified:   cabal-testsuite/PackageTests/CopyHie/cabal.out
	modified:   cabal-testsuite/PackageTests/CustomSegfault/cabal.out
	modified:   cabal-testsuite/PackageTests/CustomTestCoverage/cabal.out
	modified:   cabal-testsuite/PackageTests/CustomWithoutCabal/cabal.out
	modified:   cabal-testsuite/PackageTests/CustomWithoutCabalDefaultMain/cabal.out
	modified:   cabal-testsuite/PackageTests/Exec/cabal.out
	modified:   cabal-testsuite/PackageTests/ExecModern/cabal.out
	modified:   cabal-testsuite/PackageTests/ExternalCommand/cabal.out
	modified:   cabal-testsuite/PackageTests/ExternalCommandEnv/cabal.out
	modified:   cabal-testsuite/PackageTests/ExternalCommandExitCode/cabal.out
	modified:   cabal-testsuite/PackageTests/ExternalCommandHelp/cabal.out
	modified:   cabal-testsuite/PackageTests/ExtraPackages/cabal.out
	modified:   cabal-testsuite/PackageTests/ExtraProgPath/setup.out
	modified:   cabal-testsuite/PackageTests/FFI/CSourceDependsStub/cabal.out
	modified:   cabal-testsuite/PackageTests/FFI/ForeignOptsC/cabal.out
	modified:   cabal-testsuite/PackageTests/FFI/ForeignOptsCxx/cabal.out
	modified:   cabal-testsuite/PackageTests/HaddockArgs/hoogle.out
	modified:   cabal-testsuite/PackageTests/HaddockArgs/quickjump.out
	modified:   cabal-testsuite/PackageTests/HaddockBuildDepends/cabal.out
	modified:   cabal-testsuite/PackageTests/HaddockProject/haddock-project.out
	modified:   cabal-testsuite/PackageTests/HaddockWarn/cabal.out
	modified:   cabal-testsuite/PackageTests/InternalLibraries/cabal-per-package.out
	modified:   cabal-testsuite/PackageTests/InternalLibraries/cabal.out
	modified:   cabal-testsuite/PackageTests/JS/JsSources/other-arch.out
	modified:   cabal-testsuite/PackageTests/JS/JsSourcesExe/other-arch.out
	modified:   cabal-testsuite/PackageTests/ListBin/SelectedComponent/cabal.out
	modified:   cabal-testsuite/PackageTests/MultiRepl/CabalMacros/cabal.out
	modified:   cabal-testsuite/PackageTests/MultiRepl/EnabledClosure/cabal.out
	modified:   cabal-testsuite/PackageTests/MultiRepl/EnabledSucc/cabal.out
	modified:   cabal-testsuite/PackageTests/MultiRepl/ExtraOptions/cabal.out
	modified:   cabal-testsuite/PackageTests/MultiRepl/NotEnabledFail/cabal.multirepl-a.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/Failing/cabal.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/Successful/cabal.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/cabal.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/T6083PostMixin/cabal.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/cabal.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/cabal.out
	modified:   cabal-testsuite/PackageTests/MultipleLibraries/T6894/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdBench/MultipleBenchmarks/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdBench/OptionsFlag/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdBench/WarningRTS/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdBuild/OnlyConfigure/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdExec/GhcInvocation/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdExec/RunExe/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRepl/CustomSetup/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/Datafiles/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/ExeAndLib/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/ExitCodePropagation/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/MultipleExes/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/MultiplePackages/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/RunMainBad/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/Script/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/ScriptBad/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/ScriptLiterate/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/Single/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdRun/WarningRTS/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdTest/OptionsFlag/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/CmdTest/WarningRTS/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/MonitorCabalFiles/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/T3827/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/T3978/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/T4017/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/T4405/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/T4477/cabal.out
	modified:   cabal-testsuite/PackageTests/NewBuild/T8875/cabal.out
	modified:   cabal-testsuite/PackageTests/NewConfigure/ConfigFile/cabal.out
	modified:   cabal-testsuite/PackageTests/NewConfigure/LocalConfigOverwrite/cabal.out
	modified:   cabal-testsuite/PackageTests/NewFreeze/BuildTools/new_freeze.out
	modified:   cabal-testsuite/PackageTests/NewFreeze/Flags/new_freeze.out
	modified:   cabal-testsuite/PackageTests/NewFreeze/FreezeFile/new_freeze.out
	modified:   cabal-testsuite/PackageTests/NewHaddock/DisableDoc/cabal.out
	modified:   cabal-testsuite/PackageTests/NewHaddock/Fails/cabal.out
	modified:   cabal-testsuite/PackageTests/NewHaddock/HaddockOutput/HaddockForHackageCmdOutput/cabal.out
	modified:   cabal-testsuite/PackageTests/NewHaddock/HaddockOutput/HaddockOutputCmd/cabal.out
	modified:   cabal-testsuite/PackageTests/NewHaddock/HaddockOutput/HaddockOutputConfig/cabal.out
	modified:   cabal-testsuite/PackageTests/NewHaddock/ImplyDependencies/cabal.out
	modified:   cabal-testsuite/PackageTests/NewSdist/DeterministicTrivial/deterministic.out
	modified:   cabal-testsuite/PackageTests/NewSdist/Globbing/cabal.out
	modified:   cabal-testsuite/PackageTests/NewSdist/ManyDataFiles/many-data-files.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/all-output-dir.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/all-test-sute.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/all.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/list-sources-output-dir.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/multi-archive-to-stdout.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/multi-list-sources.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/multi-target.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/target-remote-package.out
	modified:   cabal-testsuite/PackageTests/NewSdist/MultiTarget/valid-and-test-suite.out
	modified:   cabal-testsuite/PackageTests/NewSdist/NullTerminated/cabal.out
	modified:   cabal-testsuite/PackageTests/OfflineFlag/offlineFlag.out
	modified:   cabal-testsuite/PackageTests/PackageDB/cabal-fail-no-base.out
	modified:   cabal-testsuite/PackageTests/PackageDB/cabal-fail-no-p.out
	modified:   cabal-testsuite/PackageTests/PackageDB/cabal-fail-no-packagedbs.out
	modified:   cabal-testsuite/PackageTests/PackageDB/cabal-manual-packagedb.out
	modified:   cabal-testsuite/PackageTests/PackageDB/cabal-packagedb.out
	modified:   cabal-testsuite/PackageTests/Path/Config/cabal.out
	modified:   cabal-testsuite/PackageTests/Project/CoverageProject/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T4154/install-time-with-constraint.out
	modified:   cabal-testsuite/PackageTests/Regression/T4202/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T4720/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T4798/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T4986/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T5213/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T5213ExeCoverage/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T5309/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T5318/sdist-list-sources.out
	modified:   cabal-testsuite/PackageTests/Regression/T5677/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6334/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6440/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6853/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6961/DepExternal/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6961/DepInternal/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6961/Exe/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T6961/Test/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T7234/Fail/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T7234/Success/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T8507/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T9640/cabal.out
	modified:   cabal-testsuite/PackageTests/Regression/T9756/cabal.out
	modified:   cabal-testsuite/PackageTests/RelativePathProjectImports/cabal.out
	modified:   cabal-testsuite/PackageTests/ReplNoLoad/cabal.exec-no-load.out
	modified:   cabal-testsuite/PackageTests/ReplNoLoad/cabal.exec-normal.out
	modified:   cabal-testsuite/PackageTests/ReplNoLoad/cabal.lib-no-load.out
	modified:   cabal-testsuite/PackageTests/ReplNoLoad/cabal.lib-normal.out
	modified:   cabal-testsuite/PackageTests/ReplOptions/cabal.multiple-repl-options-multiple-flags.out
	modified:   cabal-testsuite/PackageTests/ReplOptions/cabal.multiple-repl-options.out
	modified:   cabal-testsuite/PackageTests/ReplOptions/cabal.single-repl-options-multiple-flags-negative.out
	modified:   cabal-testsuite/PackageTests/ReplOptions/cabal.single-repl-options-multiple-flags.out
	modified:   cabal-testsuite/PackageTests/ReplOptions/cabal.single-repl-options.out
	modified:   cabal-testsuite/PackageTests/SDist/T5195and5349/cabal.out
	modified:   cabal-testsuite/PackageTests/SDist/T7028/cabal.out
	modified:   cabal-testsuite/PackageTests/SDist/T7124/cabal-list.out
	modified:   cabal-testsuite/PackageTests/SDist/T7124/cabal.out
	modified:   cabal-testsuite/PackageTests/SDist/T7698/cabal.out
	modified:   cabal-testsuite/PackageTests/SDist/T8817/cabal.out
	modified:   cabal-testsuite/PackageTests/ShowBuildInfo/A/build-info-all.out
	modified:   cabal-testsuite/PackageTests/ShowBuildInfo/A/build-info-exe.out
	modified:   cabal-testsuite/PackageTests/ShowBuildInfo/A/remove-outdated.out
	modified:   cabal-testsuite/PackageTests/ShowBuildInfo/CompileFail/compile-fail.out
	modified:   cabal-testsuite/PackageTests/ShowBuildInfo/Complex/single.out
	modified:   cabal-testsuite/PackageTests/TestCodeGenerator/cabal.out
	modified:   cabal-testsuite/PackageTests/TestSuiteTests/ExeV10/cabal.out
	modified:   cabal-testsuite/PackageTests/TestSuiteTests/ExeV10/coverage.out
	modified:   cabal-testsuite/PackageTests/VersionPriority/0-local.out
	modified:   cabal-testsuite/PackageTests/VersionPriority/1-local.out
	modified:   cabal-testsuite/PackageTests/VersionPriority/1-web.out
	modified:   cabal-testsuite/PackageTests/VersionPriority/2-local.out
	modified:   cabal-testsuite/PackageTests/VersionPriority/2-web.out
	modified:   cabal-testsuite/PackageTests/VersionPriority/3-web.out
	new file:   changelog.d/pr-10507

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   cabal-testsuite/PackageTests/MultiRepl/CustomSetupKeepTempFiles/cabal.no.out
	deleted by us:   cabal-testsuite/PackageTests/MultiRepl/CustomSetupKeepTempFiles/cabal.yes.out
	deleted by us:   cabal-testsuite/PackageTests/MultiRepl/KeepTempFiles/cabal.no.out
	deleted by us:   cabal-testsuite/PackageTests/MultiRepl/KeepTempFiles/cabal.yes.out
	deleted by us:   cabal-testsuite/PackageTests/NewBuild/CmdClean/CleanSourceRepositoryPackage/cabal.out

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally