priv deps: Don't component qualify private scopes

Originally, we were qualifying a private dependency with the component
with that private dep. Now, we qualify a private dependency without the
component, i.e. only with the package name and the scope name.

However, we want the same private scope name to be shared across all
components of a package (and, if different dependencies are desired
across components, different scope names should be used). For example,
the following package should not be possible to solve (and does not with
this commit):

    cabal-version:   3.0
    name:            pkgC
    version:         0.1.0.0
    build-type:      Simple

    library
        private-build-depends: SameName with (libA == 0.1.0.0)
        build-depends:    base

    executable myexe
        private-build-depends: SameName with (libA == 0.2.0.0)
        build-depends: base

See the second case of the `same-scope-name` test.

cabal-install-solver/src/Distribution/Solver/Modular/ConfiguredConversion.hs

@@ -75,7 +75,7 @@ convConfId parent (PI (Q (PackagePath ns qn) pn) (I v loc)) =
           -- As below, we need to identify where `AliasPkg` applies. This is
           -- needed to qualify `solverPkgLibDeps` since we may have multiple
           -- instances of the same package qualified.
-          | QualAlias pn' _ alias <- qn
+          | QualAlias pn' alias <- qn
           , parent == Just pn' -> AliasPkg (PreExistingId sourceId pi) alias
 
           | otherwise
@@ -84,7 +84,7 @@ convConfId parent (PI (Q (PackagePath ns qn) pn) (I v loc)) =
           -- Same reasoning as for exes, the "top" qualified goal is the one
           -- which is private and needs to be aliased, but there might be other goals underneath which
           -- are solved in the same scope (but are not private)
-          | QualAlias pn' _ alias <- qn
+          | QualAlias pn' alias <- qn
           , parent == Just pn' -> AliasPkg (PlannedId sourceId) alias
 
           | IndependentBuildTool _ pn' <- ns

cabal-install-solver/src/Distribution/Solver/Modular/Dependency.hs

@@ -204,7 +204,7 @@ qualifyDeps QO{..} rdm (Q pp@(PackagePath ns q) pn) = go
     goD (Dep dep@(PkgComponent qpn (ExposedExe _)) is_private ci) _ =
         Dep (Q (PackagePath (IndependentBuildTool pn qpn) QualToplevel) <$> dep) is_private ci
     goD (Dep dep@(PkgComponent qpn (ExposedLib _)) is_private ci) comp
-      | Private pq <- is_private  = Dep (Q (PackagePath ns (QualAlias pn comp pq))  <$> dep) is_private ci
+      | Private pq <- is_private  = Dep (Q (PackagePath ns (QualAlias pn pq))  <$> dep) is_private ci
       | qBase qpn   = Dep (Q (PackagePath ns (QualBase pn)) <$> dep) is_private ci
       | qSetup comp = Dep (Q (PackagePath (IndependentComponent pn ComponentSetup) QualToplevel) <$> dep) is_private ci
       | otherwise   = Dep (Q (PackagePath ns (inheritedQ qpn)    ) <$> dep) is_private ci

cabal-install-solver/src/Distribution/Solver/Modular/PrivateScopeClosure.hs

@@ -235,7 +235,7 @@ findBadPrivClosures pkg rdm =
         --
         --  * If it is not the same private scope, but in one nonetheless,
         --  we've reached an end and none of the packages accumulated.
-        | Q (PackagePath _ ps@(QualAlias _ _ _)) _ <- next
+        | Q (PackagePath _ ps@(QualAlias _ _)) _ <- next
         = if ps == bad_scope_qual
              then assert (not $ null acc) acc
              else []

cabal-install-solver/src/Distribution/Solver/Types/PackageConstraint.hs

@@ -87,7 +87,7 @@ constraintScopeMatches (ScopeTarget pn) (Q (PackagePath ns q) pn') =
       namespaceMatches (IndependentBuildTool {}) = False
   in namespaceMatches ns && q == QualToplevel && pn == pn'
 constraintScopeMatches (ScopePrivate spn alias c_pn) (Q (PackagePath _qual_ns q) c_pn') =
-  let qualMatches (QualAlias qual_pn _ qual_alias) = spn == qual_pn && alias == qual_alias
+  let qualMatches (QualAlias qual_pn qual_alias) = spn == qual_pn && alias == qual_alias
       qualMatches _ = False
     -- TODO: Check whether any ns should subsume qual_ns (if private constraint scopes grow namespaces...)
   in qualMatches q && c_pn == c_pn'

cabal-install-solver/src/Distribution/Solver/Types/PackagePath.hs

@@ -60,7 +60,7 @@ data Qualifier =
   | QualBase PackageName
 
   -- A goal which is solved per-component
-  | QualAlias PackageName Component PrivateAlias
+  | QualAlias PackageName PrivateAlias
 
   deriving (Eq, Ord, Show)
 
@@ -75,7 +75,7 @@ data Qualifier =
 dispQualifier :: Qualifier -> Disp.Doc
 dispQualifier QualToplevel = Disp.empty
 dispQualifier (QualBase pn)  = pretty pn <<>> Disp.text ".bb."
-dispQualifier (QualAlias pn c alias) = pretty pn <<>> Disp.text ":" <<>> pretty c <<>> Disp.text ":" <<>> pretty alias <<>> Disp.text "."
+dispQualifier (QualAlias pn alias) = pretty pn <<>> Disp.text ":" <<>> pretty alias <<>> Disp.text "."
 
 instance Pretty Qualifier where
   pretty = dispQualifier

cabal-testsuite/PackageTests/PrivateDeps/same-scope-name/cabal.test.hs

@@ -17,13 +17,21 @@ because of the conflict too
 main =
   cabalTest $ recordMode DoNotRecord $ do
     -- withProjectFile "cabal.project.scenea" $ -- For some reason this doesn't work...
+
       withRepo "repo" $ do
         -- Succeeds because SameName from pkgA and SameName from pkgB do not collide.
-        cabal "build" ["pkgA", "--project-file=cabal.project.scenea"]
+        out <- cabal' "build" ["pkgA", "--project-file=cabal.project.scenea"]
+        -- We build the two versions, one for each package's private deps.
+        assertOutputContains "- libA-0.1.0.0 (lib) (requires build)" out
+        assertOutputContains "- libA-0.2.0.0 (lib) (requires build)" out
+
       withRepo "repo" $ do
         -- Fails because SameName from pkgC in its two separate components
-        cabal "build" ["pkgC", "--project-file=cabal.project.sceneb"]
+        fails (cabal' "build" ["pkgC", "--project-file=cabal.project.sceneb"])
+        >>= assertOutputContains "rejecting: pkgC:SameName.libA-0.2.0.0 (conflict: pkgC => pkgC:SameName.libA==0.1.0.0)"
+
       withRepo "repo" $ do
         -- Fails because SameName from pkgD in the same component
-        cabal "build" ["pkgD", "--project-file=cabal.project.scenec"]
+        fails (cabal'  "build" ["pkgD", "--project-file=cabal.project.scenec"])
+        >>= assertOutputContains "rejecting: pkgD:SameName.libA-0.2.0.0 (conflict: pkgD => pkgD:SameName.libA==0.1.0.0)"