Remove GHCup vanilla channel from defaults

Author: andreasabel

dist/index.js

@@ -43,7 +43,14 @@ export default async function run(
     await core.group(`Preparing ghcup environment`, async () => {
       // Andreas Abel, 2026-01-01, https://github.com/haskell-actions/setup/issues/78
       // Add ghcup vanilla and prereleases channels by default.
-      await addGhcupReleaseChannel('vanilla', os, arch);
+      // Andreas Abel, 2026-01-11, https://github.com/haskell-actions/setup/issues/136
+      // There are reasons not to include the vanilla channel by default:
+      // mpickering write:
+      // the "vanilla" channel is the bindists "as released by GHC upstream",
+      // which is a change from the default, which provides curated bindists.
+      // In particular on the cabal repo this meant a 9.0.2 bindist without
+      // profiling libraries was downloaded by CI and caused a test to fail.
+      // await addGhcupReleaseChannel('vanilla', os, arch);
       await addGhcupReleaseChannel('prereleases', os, arch);
       if (opts.ghcup.releaseChannel)
         await addGhcupReleaseChannel(