issues: file 0127 — namespaced generic call's result mis-types as the unbound T stub

issues/0127-namespaced-generic-call-result-unbound-stub.md

@@ -0,0 +1,61 @@
+# 0127: namespaced generic call's result mis-types as the unbound `T` stub
+
+## Symptom
+
+A NAMESPACED call to a generic free function returns a value typed as the
+unbound `T` empty-struct stub instead of the bound concrete type.
+
+- **Observed**: `print("{}\n", m.pick(3, 9))` prints `T{}` — the Any boxing
+  tags the result with the unbound `T` stub type.
+- **Expected**: prints `9`.
+
+The same call through a FLAT import (`pick(3, 9)`) prints `9` — only the
+namespaced spelling (`field_access` callee whose object is a namespace
+alias) mis-types the result.
+
+## Reproduction
+
+m.sx:
+
+```sx
+#import "modules/std.sx";
+
+pick :: (a: $T, b: T) -> T {
+    if a > b then a else b
+}
+```
+
+main.sx:
+
+```sx
+#import "modules/std.sx";
+m :: #import "m.sx";
+
+main :: () {
+    print("{}\n", m.pick(3, 9));
+}
+```
+
+Observed at master 309f48e: prints `T{}`. The flat-import spelling of the
+same call prints `9`.
+
+## Investigation prompt
+
+Suspected area: the namespaced/qualified dispatch leg in
+`src/ir/lower/call.zig` `lowerCall` (the qualified `fn_ast_map` paths)
+and/or the generic return-type inference not being consulted for the
+namespaced callee shape. The plain-identifier path routes the call's
+result typing through `buildTypeBindings` (the one binding builder —
+see a47ea14's note); the namespaced path appears to stamp the declared
+return type (`T`) without substituting the call's inferred bindings, so
+the result carries the unbound-`T` stub struct into Any boxing.
+
+Fix: make the namespaced generic call derive its result type from the
+call's inferred `$T → concrete` bindings exactly like the flat path.
+Check whether the value itself is computed correctly (the mono body) and
+only the recorded result TYPE is wrong, or whether dispatch skipped
+monomorphization entirely.
+
+Verification: the repro prints `9`; the flat spelling still prints `9`;
+`zig build && zig build test`, `bash tests/run_examples.sh` green; pin
+the repro as a generics example (next free 02xx number).