Add errors for future and missing index-states

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

@@ -258,7 +258,7 @@ updateRepo verbosity _updateFlags repoCtxt (repo, indexState) = do
     RepoSecure{} -> repoContextWithSecureRepo repoCtxt repo $ \repoSecure -> do
       let index = RepoIndex repoCtxt repo
       -- NB: This may be a NoTimestamp if we've never updated before
-      current_ts <- currentIndexTimestamp (lessVerbose verbosity) repoCtxt repo
+      current_ts <- currentIndexTimestamp (lessVerbose verbosity) index
       -- NB: always update the timestamp, even if we didn't actually
       -- download anything
       writeIndexTimestamp index indexState

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

@@ -25,6 +25,9 @@ import Data.ByteString (ByteString)
 import qualified Data.ByteString.Base16 as Base16
 import qualified Data.ByteString.Char8 as BS8
 import Data.List (groupBy)
+import Distribution.Client.IndexUtils.Timestamp
+import Distribution.Client.Types.Repo
+import Distribution.Client.Types.RepoName (RepoName (..))
 import Distribution.Compat.Prelude
 import Distribution.Deprecated.ParseUtils (PWarning, showPWarning)
 import Distribution.Package
@@ -179,6 +182,8 @@ data CabalInstallException
   | FreezeException String
   | PkgSpecifierException [String]
   | CorruptedIndexCache String
+  | UnusableIndexState RemoteRepo Timestamp Timestamp
+  | MissingPackageList RemoteRepo
   deriving (Show, Typeable)
 
 exceptionCodeCabalInstall :: CabalInstallException -> Int
@@ -327,6 +332,8 @@ exceptionCodeCabalInstall e = case e of
   FreezeException{} -> 7156
   PkgSpecifierException{} -> 7157
   CorruptedIndexCache{} -> 7158
+  UnusableIndexState{} -> 7159
+  MissingPackageList{} -> 7160
 
 exceptionMessageCabalInstall :: CabalInstallException -> String
 exceptionMessageCabalInstall e = case e of
@@ -828,6 +835,20 @@ exceptionMessageCabalInstall e = case e of
   FreezeException errs -> errs
   PkgSpecifierException errorStr -> unlines errorStr
   CorruptedIndexCache str -> str
+  UnusableIndexState repoRemote maxFound requested ->
+    "Latest known index-state for '"
+      ++ unRepoName (remoteRepoName repoRemote)
+      ++ "' ("
+      ++ prettyShow maxFound
+      ++ ") is older than the requested index-state ("
+      ++ prettyShow requested
+      ++ ").\nRun 'cabal update' or set the index-state to a value at or before "
+      ++ prettyShow maxFound
+      ++ "."
+  MissingPackageList repoRemote ->
+    "The package list for '"
+      ++ unRepoName (remoteRepoName repoRemote)
+      ++ "' does not exist. Run 'cabal update' to download it."
 
 instance Exception (VerboseException CabalInstallException) where
   displayException :: VerboseException CabalInstallException -> [Char]

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

@@ -318,21 +318,31 @@ getSourcePackagesAtIndexState verbosity repoCtxt mb_idxState mb_activeRepos = do
       IndexStateHead -> do
         info verbosity ("index-state(" ++ unRepoName rname ++ ") = " ++ prettyShow (isiHeadTime isi))
         return ()
-      IndexStateTime ts0 -> do
+      IndexStateTime ts0 ->
         -- isiMaxTime is the latest timestamp in the filtered view returned by
         -- `readRepoIndex` above. It is always true that isiMaxTime is less or
         -- equal to a requested IndexStateTime. When `isiMaxTime isi /= ts0` (or
         -- equivalently `isiMaxTime isi < ts0`) it means that ts0 falls between
         -- two timestamps in the index.
         when (isiMaxTime isi /= ts0) $
-          info verbosity $
-            "There is no index-state for '"
-              ++ unRepoName rname
-              ++ "' exactly at the requested timestamp ("
-              ++ prettyShow ts0
-              ++ "). Falling back to the previous index-state that exists: "
-              ++ prettyShow (isiMaxTime isi)
-
+          let commonMsg =
+                "There is no index-state for '"
+                  ++ unRepoName rname
+                  ++ "' exactly at the requested timestamp ("
+                  ++ prettyShow ts0
+                  ++ "). "
+           in if isNothing $ timestampToUTCTime (isiMaxTime isi)
+                then
+                  warn verbosity $
+                    commonMsg
+                      ++ "Also, there are no index-states before the one requested, so the repository '"
+                      ++ unRepoName rname
+                      ++ "' will be empty."
+                else
+                  info verbosity $
+                    commonMsg
+                      ++ "Falling back to the previous index-state that exists: "
+                      ++ prettyShow (isiMaxTime isi)
     pure
       RepoData
         { rdRepoName = rname
@@ -450,8 +460,8 @@ readRepoIndex verbosity repoCtxt repo idxState =
       if isDoesNotExistError e
         then do
           case repo of
-            RepoRemote{..} -> die' verbosity $ errMissingPackageList repoRemote
-            RepoSecure{..} -> die' verbosity $ errMissingPackageList repoRemote
+            RepoRemote{..} -> dieWithException verbosity $ MissingPackageList repoRemote
+            RepoSecure{..} -> dieWithException verbosity $ MissingPackageList repoRemote
             RepoLocalNoIndex local _ ->
               warn verbosity $
                 "Error during construction of local+noindex "
@@ -465,40 +475,26 @@ readRepoIndex verbosity repoCtxt repo idxState =
     isOldThreshold = 15 -- days
     warnIfIndexIsOld dt = do
       when (dt >= isOldThreshold) $ case repo of
-        RepoRemote{..} -> warn verbosity $ errOutdatedPackageList repoRemote dt
-        RepoSecure{..} -> warn verbosity $ errOutdatedPackageList repoRemote dt
+        RepoRemote{..} -> warn verbosity $ warnOutdatedPackageList repoRemote dt
+        RepoSecure{..} -> warn verbosity $ warnOutdatedPackageList repoRemote dt
         RepoLocalNoIndex{} -> return ()
 
     dieIfRequestedIdxIsNewer isi =
       let latestTime = isiHeadTime isi
        in case idxState of
             IndexStateTime t -> when (t > latestTime) $ case repo of
               RepoSecure{..} ->
-                die' verbosity $ errRequestedIdxIsNewer repoRemote latestTime t
+                dieWithException verbosity $ UnusableIndexState repoRemote latestTime t
               RepoRemote{} -> pure ()
               RepoLocalNoIndex{} -> return ()
             IndexStateHead -> pure ()
 
-    errMissingPackageList repoRemote =
-      "The package list for '"
-        ++ unRepoName (remoteRepoName repoRemote)
-        ++ "' does not exist. Run 'cabal update' to download it."
-    errOutdatedPackageList repoRemote dt =
+    warnOutdatedPackageList repoRemote dt =
       "The package list for '"
         ++ unRepoName (remoteRepoName repoRemote)
         ++ "' is "
         ++ shows (floor dt :: Int) " days old.\nRun "
         ++ "'cabal update' to get the latest list of available packages."
-    errRequestedIdxIsNewer repoRemote maxFound req =
-      "Latest known index-state for '"
-        ++ unRepoName (remoteRepoName repoRemote)
-        ++ "' ("
-        ++ prettyShow maxFound
-        ++ ") is older than the requested index-state ("
-        ++ prettyShow req
-        ++ ").\nRun 'cabal update' or set the index-state to a value at or before "
-        ++ prettyShow maxFound
-        ++ "."
 
 -- | Return the age of the index file in days (as a Double).
 getIndexFileAge :: Repo -> IO Double
@@ -1126,7 +1122,7 @@ readIndexCache verbosity index = do
 --
 -- If a corrupted index cache is detected this function regenerates
 -- the index cache and then reattempts to read the index once (and
--- 'die's if it fails again). Throws IOException if any arise.
+-- 'dieWithException's if it fails again). Throws IOException if any arise.
 readNoIndexCache :: Verbosity -> Index -> IO NoIndexCache
 readNoIndexCache verbosity index = do
   cacheOrFail <- readNoIndexCache' index