Always have the project itself sort first

- Use with-ghc.config with woops project

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

@@ -56,6 +56,15 @@ newtype ProjectConfigPath = ProjectConfigPath (NonEmpty FilePath)
 instance Ord ProjectConfigPath where
     compare pa@(ProjectConfigPath (NE.toList -> as)) pb@(ProjectConfigPath (NE.toList -> bs)) =
         case (as, bs) of
+            -- There should only ever be one root project path, only one path
+            -- with length 1. Comparing it to itself should be EQ. Don't assume
+            -- this though, do a comparison anyway when both sides have length
+            -- 1.  The root path, the project itself, should always be the first
+            -- path in a sorted listing.
+            ([a], [b]) -> compare a b
+            ([_], _) -> LT
+            (_, [_]) -> GT
+
             (a:_, b:_) -> case (parseAbsoluteURI a, parseAbsoluteURI b) of
                 (Just ua, Just ub) -> compare ua ub P.<> compare aImporters bImporters
                 (Just _, Nothing) -> GT

cabal-testsuite/PackageTests/ConditionalAndImport/cabal.out

@@ -67,9 +67,9 @@ cyclical import of cyclical-2-out-out-self-b.config;
 # checking that cyclical check doesn't false-positive on same file names in different folders; hoping within a folder and then into a subfolder
 # cabal v2-build
 Configuration is affected by the following files:
+- noncyclical-same-filename-a.project
 - noncyclical-same-filename-a.config
     imported by: noncyclical-same-filename-a.project
-- noncyclical-same-filename-a.project
 - same-filename/noncyclical-same-filename-a.config
     imported by: noncyclical-same-filename-a.config
     imported by: noncyclical-same-filename-a.project
@@ -83,10 +83,10 @@ Building library for my-0.1...
 # checking that cyclical check doesn't false-positive on same file names in different folders; hoping into a subfolder and then back out again
 # cabal v2-build
 Configuration is affected by the following files:
+- noncyclical-same-filename-b.project
 - noncyclical-same-filename-b.config
     imported by: same-filename/noncyclical-same-filename-b.config
     imported by: noncyclical-same-filename-b.project
-- noncyclical-same-filename-b.project
 - same-filename/noncyclical-same-filename-b.config
     imported by: noncyclical-same-filename-b.project
 Up to date
@@ -383,6 +383,8 @@ Up to date
 # cabal v2-build
 Configuration is affected by the following files:
 - woops-0.project
+- with-ghc.config
+    imported by: woops-0.project
 - woops-2.config
     imported by: woops/woops-1.config
     imported by: woops-0.project
@@ -649,12 +651,7 @@ Configuration is affected by the following files:
     imported by: woops/woops-1.config
     imported by: woops-0.project
 Resolving dependencies...
-Build profile: -w ghc-9.4.8 -O1
-In order, the following will be built:
- - my-0.1 (lib:my) (first run)
-Configuring my-0.1...
-Preprocessing library for my-0.1...
-Building library for my-0.1...
+Up to date
 # checking "using config from message" without URI imports
 # cabal v2-build
 # checking "using config from message" with URI imports

cabal-testsuite/PackageTests/ConditionalAndImport/cabal.test.hs

@@ -310,6 +310,7 @@ main = cabalTest . withRepo "repo" . recordMode RecordMarked $ do
       "Project configuration with URI imports is listed in full"
       "When using configuration from:(\n|\r\n) \
         \ .*woops-0\\.project(\n|\r\n) \
+        \ .*with-ghc\\.config(\n|\r\n) \
         \ .*woops-2\\.config(\n|\r\n) \
         \ .*woops-4\\.config(\n|\r\n) \
         \ .*woops-6\\.config(\n|\r\n) \

cabal-testsuite/PackageTests/ConditionalAndImport/with-ghc.config

@@ -0,0 +1,7 @@
+-- WARNING: Override the `with-compiler: ghc-x.y.z` of the stackage import, of
+-- https://www.stackage.org/nightly-yyyy-mm-dd/cabal.config. Otherwise tests
+-- will fail with:
+--   -Error: [Cabal-5490]
+--   -Cannot find the program 'ghc'. User-specified path 'ghc-x.y.z' does not
+--    refer to an executable and the program is not on the system path.
+with-compiler: ghc

cabal-testsuite/PackageTests/ConditionalAndImport/woops-0.project

@@ -5,3 +5,5 @@ import: woops/woops-3.config
 import: woops/woops-5.config
 import: woops/woops-7.config
 import: woops/woops-9.config
+
+import: with-ghc.config