Merge remote-tracking branch 'origin/trunk' into fix/2133

parser-typechecker/src/Unison/Runtime/ANF.hs

@@ -1030,11 +1030,15 @@ anfBlock (Match' scrut cas) = do
             mdf
     AccumEmpty -> pure (sctx <> cx, pure $ TMatch v MatchEmpty)
 anfBlock (Let1Named' v b e)
-  = anfBlock b >>= \(bctx, (d0, cb)) -> bindLocal [v] $ do
-      (ectx, ce) <- anfBlock e
-      d <- bindDirection d0
-      let octx = bctx <> directed [ST1 d v BX cb] <> ectx
-      pure (octx, ce)
+  = anfBlock b >>= \case
+      (bctx, (Direct, TVar u)) -> do
+        (ectx, ce) <- anfBlock e
+        pure (bctx <> ectx, ABTN.rename v u <$> ce)
+      (bctx, (d0, cb)) -> bindLocal [v] $ do
+        (ectx, ce) <- anfBlock e
+        d <- bindDirection d0
+        let octx = bctx <> directed [ST1 d v BX cb] <> ectx
+        pure (octx, ce)
 anfBlock (Apps' f args) = do
   (fctx, (d, cf)) <- anfFunc f
   (actx, cas) <- anfArgs args

parser-typechecker/src/Unison/Runtime/MCode.hs

@@ -916,7 +916,7 @@ emitLet _   grp _   _ _   ctx (TApp (FPrim p) args)
   = fmap (Ins . either emitPOp emitFOp p $ emitArgs grp ctx args)
 emitLet rns grp rec d vcs ctx bnd
   | Direct <- d
-  = internalBug $ "unsupported compound direct let" ++ show bnd
+  = internalBug $ "unsupported compound direct let: " ++ show bnd
   | Indirect w <- d
   = \esect ->
       f <$> emitSection rns grp rec (Block ctx) bnd

unison-src/transcripts/fix2187.md

@@ -0,0 +1,19 @@
+```ucm:hide
+.> builtins.mergeio
+```
+
+```unison 
+
+lexicalScopeEx: [Text]
+lexicalScopeEx = 
+  parent = "outer"
+  inner1 = let 
+    child1 = "child1"
+    inner2 : [Text]
+    inner2 = let 
+      child2 = "child2"
+      [parent, child1, child2]
+    inner2
+  inner1
+
+```

unison-src/transcripts/fix2187.output.md

@@ -0,0 +1,26 @@
+```unison
+lexicalScopeEx: [Text]
+lexicalScopeEx = 
+  parent = "outer"
+  inner1 = let 
+    child1 = "child1"
+    inner2 : [Text]
+    inner2 = let 
+      child2 = "child2"
+      [parent, child1, child2]
+    inner2
+  inner1
+
+```
+
+```ucm
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These new definitions are ok to `add`:
+    
+      lexicalScopeEx : [Text]
+
+```