Support x86-64 only downloads

lib/SlackBuilder/Config.hs

@@ -1,3 +1,4 @@
+-- | Configuration file.
 module SlackBuilder.Config
     ( Settings(..)
     , MaintainerSettings(..)

lib/SlackBuilder/Info.hs

@@ -1,3 +1,4 @@
+-- | Info file parsing and printing.
 module SlackBuilder.Info
     ( PackageInfo(..)
     , generate
@@ -113,7 +114,7 @@ generate pkg = Lazy.Text.toStrict $ Text.Builder.toLazyText builder
     builder = "PRGNAM=\"" <> Text.Builder.fromString (pkgname pkg) <> "\"\n"
         <> "VERSION=\"" <> Text.Builder.fromText (version pkg) <> "\"\n"
         <> "HOMEPAGE=\"" <> Text.Builder.fromText (homepage pkg) <> "\"\n"
-        <> generateMultiEntry "DOWNLOAD" (render <$> downloads pkg)
+        <> downloadEntry
         <> generateMultiEntry "MD5SUM" (digestToText <$> checksums pkg)
         <> generateMultiEntry "DOWNLOAD_x86_64" (render <$> downloadX64 pkg)
         <> generateMultiEntry "MD5SUM_x86_64" (digestToText <$> checksumX64 pkg)
@@ -122,6 +123,10 @@ generate pkg = Lazy.Text.toStrict $ Text.Builder.toLazyText builder
         <> "EMAIL=\"" <> Text.Builder.fromText (email pkg) <> "\"\n"
     fromByteStringWords = Text.Builder.fromText
         . Text.unwords . fmap Text.decodeUtf8
+    downloadEntry
+        | null $ downloads pkg
+        , not $ null $ downloadX64 pkg = "DOWNLOAD=\"UNSUPPORTED\"\n"
+        | otherwise = generateMultiEntry "DOWNLOAD" $ render <$> downloads pkg
 
 generateMultiEntry :: Text -> [Text] -> Text.Builder
 generateMultiEntry name entries = Text.Builder.fromText name

lib/SlackBuilder/Trans.hs

@@ -1,3 +1,4 @@
+-- | Transformers and exceptions.
 module SlackBuilder.Trans
     ( SlackBuilderException(..)
     , SlackBuilderT(..)