Add "when using config from" tests

cabal-testsuite/PackageTests/ConditionalAndImport/cabal.out

@@ -655,6 +655,10 @@ In order, the following will be built:
 Configuring my-0.1...
 Preprocessing library for my-0.1...
 Building library for my-0.1...
+# checking "using config from message" without URI imports
+# cabal v2-build
+# checking "using config from message" with URI imports
+# cabal v2-build
 # checking bad conditional
 # cabal v2-build
 Error: [Cabal-7090]

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

@@ -261,6 +261,71 @@ main = cabalTest . withRepo "repo" . recordMode RecordMarked $ do
   log "checking if we detect when the same config is imported via many different paths (we don't)"
   woopping <- cabal' "v2-build" [ "--project-file=woops-0.project" ]
 
+  log "checking \"using config from message\" without URI imports"
+  withDirectory "yops" $ do
+    yopping <- fails $ cabal' "v2-build" [ "--project-file=../yops-0.project" ]
+
+    -- Use assertRegex when the output is tainted by the temp directory, like
+    -- this:
+    --
+    --   When using configuration from:
+    --   - /tmp/cabal-testsuite-286573/yops-0.project
+    --   - /tmp/cabal-testsuite-286573/yops-2.config etc
+    assertRegex
+      "Project configuration is listed in full"
+      "When using configuration from:\n \
+        \ .*yops-0\\.project\n \
+        \ .*yops-2\\.config\n \
+        \ .*yops-4\\.config\n \
+        \ .*yops-6\\.config\n \
+        \ .*yops-8\\.config\n \
+        \ .*yops-1\\.config\n \
+        \ .*yops-3\\.config\n \
+        \ .*yops-5\\.config\n \
+        \ .*yops-7\\.config\n \
+        \ .*yops-9\\.config\n"
+      yopping
+
+    assertOutputContains
+      (normalizeWindowsOutput "The following errors occurred: \
+      \  - The package directory '.' does not contain any .cabal file.")
+      yopping
+
+    return ()
+
+  log "checking \"using config from message\" with URI imports"
+  withDirectory "woops" $ do
+    woopping <- fails $ cabal' "v2-build" [ "--project-file=../woops-0.project" ]
+
+    -- Use assertRegex when the output is tainted by the temp directory, like
+    -- this:
+    --
+    --   When using configuration from:
+    --   - /tmp/cabal-testsuite-282695/woops-0.project
+    --   - /tmp/cabal-testsuite-282695/woops-2.config etc
+    assertRegex
+      "Project configuration is listed in full"
+      "When using configuration from:\n \
+        \ .*woops-0\\.project\n \
+        \ .*woops-2\\.config\n \
+        \ .*woops-4\\.config\n \
+        \ .*woops-6\\.config\n \
+        \ .*woops-8\\.config\n \
+        \ .*woops-1\\.config\n \
+        \ .*woops-3\\.config\n \
+        \ .*woops-5\\.config\n \
+        \ .*woops-7\\.config\n \
+        \ .*woops-9\\.config\n \
+        \ .*https://www.stackage.org/lts-21.25/cabal.config\n"
+      woopping
+
+    assertOutputContains
+      (normalizeWindowsOutput "The following errors occurred: \
+      \  - The package directory '.' does not contain any .cabal file.")
+      woopping
+
+    return ()
+
   log "checking bad conditional"
   badIf <- fails $ cabal' "v2-build" [ "--project-file=bad-conditional.project" ]
   assertOutputContains "Cannot set compiler in a conditional clause of a cabal project file" badIf