Implement compiling HLS from source

lib/GHCup/Download.hs

@@ -636,7 +636,7 @@ checkDigest eDigest file = do
     lift $ logInfo $ "verifying digest of: " <> T.pack p'
     c <- liftIO $ L.readFile file
     cDigest <- throwEither . E.decodeUtf8' . B16.encode . SHA256.hashlazy $ c
-    when ((cDigest /= eDigest) && verify) $ throwE (DigestError cDigest eDigest)
+    when ((cDigest /= eDigest) && verify) $ throwE (DigestError file cDigest eDigest)
 
 
 -- | Get additional curl args from env. This is an undocumented option.

lib/GHCup/Errors.hs

@@ -188,12 +188,14 @@ instance Pretty TarDirDoesNotExist where
     text "Tar directory does not exist:" <+> pPrint dir
 
 -- | File digest verification failed.
-data DigestError = DigestError Text Text
+data DigestError = DigestError FilePath Text Text
   deriving Show
 
 instance Pretty DigestError where
-  pPrint (DigestError currentDigest expectedDigest) =
-    text "Digest error: expected" <+> text (T.unpack expectedDigest) <+> text "but got" <+> pPrint currentDigest
+  pPrint (DigestError fp currentDigest expectedDigest) =
+    text "Digest error for" <+> text (fp <> ": expected")
+      <+> text (T.unpack expectedDigest) <+> text "but got" <+> pPrint currentDigest <+> text
+      "\nConsider removing the file in case it's cached and try again."
 
 -- | File digest verification failed.
 data GPGError = forall xs . (ToVariantMaybe DownloadFailed xs, PopVariant DownloadFailed xs, Show (V xs), Pretty (V xs)) => GPGError (V xs)

lib/GHCup/Utils.hs

@@ -842,6 +842,8 @@ runBuildAction :: ( Pretty (V e)
                   , MonadMask m
                   , HasLog env
                   , MonadUnliftIO m
+                  , MonadFail m
+                  , MonadCatch m
                   )
                => FilePath        -- ^ build directory (cleaned up depending on Settings)
                -> Maybe FilePath  -- ^ dir to *always* clean up on exception
@@ -1039,7 +1041,7 @@ ensureGlobalTools = do
   shimDownload <- liftE $ lE @_ @'[NoDownload]
     $ maybe (Left NoDownload) Right $ Map.lookup ShimGen gTools
   let dl = downloadCached' shimDownload (Just "gs.exe") Nothing
-  void $ (\(DigestError _ _) -> do
+  void $ (\(DigestError _ _ _) -> do
       lift $ logWarn "Digest doesn't match, redownloading gs.exe..."
       lift $ logDebug ("rm -f " <> T.pack (cacheDir dirs </> "gs.exe"))
       lift $ hideError doesNotExistErrorType $ recycleFile (cacheDir dirs </> "gs.exe")