Improve message and its formatting

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

@@ -1002,22 +1002,23 @@ installLibraries
         when showWarning $
           warn verbosity $
             "The libraries were installed by creating a global GHC environment file at:\n"
-              ++ "  "
-              ++ envFile
+              ++ envFile ++ "\n"
               ++ "\n"
-              ++ "The presence of such an environment file is likely to confuse other tools\n"
-              ++ "because it changes GHC's behaviour: it changes the default package set in ghc\n"
-              ++ "and ghci from its normal value (which is \"all boot libraries\"), and because GHC\n"
-              ++ "environment files are little-used, other tools might break because of it.\n"
+              ++ "The presence of such an environment file is likely to confuse or break other "
+              ++ "tools because it changes GHC's behaviour: it changes the default package set in "
+              ++ "ghc and ghci from its normal value (which is \"all boot libraries\"). GHC "
+              ++ "environment files are little-used and often not tested for.\n"
               ++ "\n"
-              ++ "Furthermore, management of these environment files is still more difficult than\n"
+              ++ "Furthermore, management of these environment files is still more difficult than "
               ++ "it could be; see e.g. https://github.com/haskell/cabal/issues/6481 .\n"
               ++ "\n"
-              ++ "Double-check that creating a global GHC environment file is really what you\n"
-              ++ "wanted! You can limit the effects of the environment by creating it in a\n"
+              ++ "Double-check that creating a global GHC environment file is really what you "
+              ++ "wanted! You can limit the effects of the environment file by creating it in a "
               ++ "specific directory using the --package-env flag. For example, use:\n"
-              ++ "  cabal install --lib <packages...> --package-env .\n"
-              ++ "to create the file in the current directory.\n"
+              ++ "\n"
+              ++ "cabal install --lib <packages...> --package-env .\n"
+              ++ "\n"
+              ++ "to create the file in the current directory."
       else
         warn verbosity $
           "The current compiler doesn't support safely installing libraries, "