cleanup and document a global repo flag

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

@@ -201,10 +201,10 @@ updateRepo verbosity _updateFlags repoCtxt (repo, indexState) = do
       writeIndexTimestamp index indexState
       -- typically we get the current time to check expiry against
       -- but if the flag is set, we don't.
-      now <- case repoContextIgnoreExpiry repoCtxt of
+      now' <- case repoContextIgnoreExpiry repoCtxt of
                  False -> Just <$> getCurrentTime
                  True  -> pure Nothing
-      updated <- Sec.uncheckClientErrors $ Sec.checkForUpdates repoSecure now
+      updated <- Sec.uncheckClientErrors $ Sec.checkForUpdates repoSecure now'
       -- this resolves indexState (which could be HEAD) into a timestamp
       new_ts <- currentIndexTimestamp (lessVerbose verbosity) repoCtxt repo
       let rname = remoteRepoName (repoRemote repo)