Document fixes and improvements

cabal-install/src/Distribution/Client/Setup.hs

@@ -2247,12 +2247,12 @@ initOptions _ =
                         (flagElim [] (fmap prettyShow)))
 
   , option ['d'] ["dependency"]
-    "Package dependency."
+    "Package dependencies. Permits comma separated list of dependencies."
     IT.dependencies
     (\v flags -> flags { IT.dependencies =
       mergeListFlag (IT.dependencies flags) v })
-    (reqArg "PACKAGE" (fmap Flag dependenciesReadE)
-                      (fmap prettyShow . fromFlagOrDefault []))
+    (reqArg "DEPENDENCIES" (fmap Flag dependenciesReadE)
+                           (fmap prettyShow . fromFlagOrDefault []))
 
   , option [] ["application-dir"]
     "Directory containing package application executable."

changelog.d/pr-8663

@@ -0,0 +1,18 @@
+synopsis:  Fix and improve list parser of cabal init cli
+packages: cabal-install
+prs: #8663
+
+description: {
+Occurrences of 'Flag [a]' seem to behave in an unexpected way. The monoid
+instance of 'Flag' is right associative and discard the value on the
+left, but we want to merge the contents of 'Flag'.
+
+Permits:
+- cabal init -d base -d vector -d containers
+
+Fixes for all Flag '[a]' the cli parser in cabal init. Adds cli parser tests.
+
+Adds the feature to specify a comma-separated list of dependencies:
+- cabal init -d base,vector,containers
+
+}