change

backend/engine/cdsl_engine/rebuild.py

@@ -38,13 +38,12 @@ def run_rebuild(cdsl: dict[str, Any], out_step: Path, ctx_file: Path | None = No
         _sketch_is_cdsl_drawable(s) for s in sketches
     )
 
-    if all_drawable and not force_exact:
-        try:
-            return _run_cdsl_only(cdsl, out_step, gold_step=gold_step)
-        except Exception as e:
-            import traceback
-            traceback.print_exc()
-            print(f"  [WARN] CDSL-only path failed: {e}, falling back")
+    cdsl_only_error: Exception | None = None
+    if all_drawable and not force_exact:
+        try:
+            return _run_cdsl_only(cdsl, out_step, gold_step=gold_step)
+        except Exception as e:
+            cdsl_only_error = e
 
     # 加载 compiler_context（后备路径）
     ctx = None
@@ -66,8 +65,13 @@ def run_rebuild(cdsl: dict[str, Any], out_step: Path, ctx_file: Path | None = No
                 "references": ir.get("references", []),
                 "validation_hints": ir.get("validation_hints", {}),
             }
-    if ctx is None and not (cdsl.get("compiler_context")):
-        raise RuntimeError("No compiler_context available and CDSL-only rebuild failed/unavailable")
+    if ctx is None and not (cdsl.get("compiler_context")):
+        if cdsl_only_error is not None:
+            raise RuntimeError(f"CDSL-only rebuild failed: {cdsl_only_error}") from cdsl_only_error
+        raise RuntimeError(
+            "CDSL-only rebuild is unavailable: every sketch must use a supported "
+            "self-contained profile."
+        )
 
     if ctx is not None:
         cdsl["compiler_context"] = ctx