Give a message that --root-cmd is not supported and --global is deprecated.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

cabal-install/Distribution/Client/Config.hs

@@ -248,6 +248,7 @@ instance Semigroup SavedConfig where
         installUpgradeDeps           = combine installUpgradeDeps,
         installOnly                  = combine installOnly,
         installOnlyDeps              = combine installOnlyDeps,
+        installRootCmd               = combine installRootCmd,
         installSummaryFile           = lastNonEmptyNL installSummaryFile,
         installLogFile               = combine installLogFile,
         installBuildReports          = combine installBuildReports,

cabal-install/Distribution/Client/Install.hs

@@ -211,6 +211,11 @@ install verbosity packageDBs repos comp platform conf useSandbox mSandboxPkgInfo
   globalFlags configFlags configExFlags installFlags haddockFlags
   userTargets0 = do
 
+    unless (installRootCmd installFlags == Cabal.NoFlag) $
+        die "--root-cmd is no longer supported, see https://github.com/haskell/cabal/issues/3353"
+    unless (fromFlag (configUserInstall configFlags)) $
+        warn verbosity "the --global flag is deprecated--it is generally considered a bad idea to install packages into the global store"
+
     installContext <- makeInstallContext verbosity args (Just userTargets0)
     planResult     <- foldProgress logMsg (return . Left) (return . Right) =<<
                       makeInstallPlan verbosity args installContext

cabal-install/Distribution/Client/ProjectConfig/Legacy.hs

@@ -402,6 +402,7 @@ convertLegacyBuildOnlyFlags globalFlags configFlags
       installDryRun             = projectConfigDryRun,
       installOnly               = _,
       installOnlyDeps           = projectConfigOnlyDeps,
+      installRootCmd            = _,
       installSummaryFile        = projectConfigSummaryFile,
       installLogFile            = projectConfigLogFile,
       installBuildReports       = projectConfigBuildReports,
@@ -498,6 +499,7 @@ convertToLegacySharedConfig
       installStrongFlags       = projectConfigStrongFlags,
       installOnly              = mempty,
       installOnlyDeps          = projectConfigOnlyDeps,
+      installRootCmd           = mempty, --no longer supported
       installSummaryFile       = projectConfigSummaryFile,
       installLogFile           = projectConfigLogFile,
       installBuildReports      = projectConfigBuildReports,

cabal-install/Distribution/Client/Setup.hs

@@ -1153,6 +1153,7 @@ data InstallFlags = InstallFlags {
     installUpgradeDeps      :: Flag Bool,
     installOnly             :: Flag Bool,
     installOnlyDeps         :: Flag Bool,
+    installRootCmd          :: Flag String,
     installSummaryFile      :: NubList PathTemplate,
     installLogFile          :: Flag PathTemplate,
     installBuildReports     :: Flag ReportLevel,
@@ -1183,6 +1184,7 @@ defaultInstallFlags = InstallFlags {
     installUpgradeDeps     = Flag False,
     installOnly            = Flag False,
     installOnlyDeps        = Flag False,
+    installRootCmd         = mempty,
     installSummaryFile     = mempty,
     installLogFile         = mempty,
     installBuildReports    = Flag NoReports,
@@ -1352,6 +1354,11 @@ installOptions showOrParseArgs =
           installOnlyDeps (\v flags -> flags { installOnlyDeps = v })
           (yesNoOpt showOrParseArgs)
 
+      , option [] ["root-cmd"]
+          "(No longer supported, do not use.)"
+          installRootCmd (\v flags -> flags { installRootCmd = v })
+          (reqArg' "COMMAND" toFlag flagToList)
+
       , option [] ["symlink-bindir"]
           "Add symlinks to installed executables into this directory."
            installSymlinkBinDir (\v flags -> flags { installSymlinkBinDir = v })