Keep the rendered file past process_fn and stop reaching for output_components

app.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
-from tempfile import TemporaryDirectory
+from tempfile import mkdtemp
 
 import gradio as gr
 import spaces
@@ -27,13 +27,18 @@ def process_fn(xml_path: str | None, use_example: bool, seed: int) -> str:
     if not xml_path and not use_example:
         raise gr.Error("Upload a MusicXML score or select the example.")
     source = xml_path or str(EXAMPLE)
-    with TemporaryDirectory(prefix="dexter-") as tmp:
-        output = Path(tmp) / "performance.mid"
-        try:
-            render(source, output, int(seed))
-        except Exception as exc:
-            raise gr.Error(f"DExter inference failed: {exc}") from exc
-        return output_components[0].move_resource_to_block_cache(str(output))
+    # mkdtemp, not a context manager: that would delete the directory on exit,
+    # taking the rendered file with it before the caller can read it, which is
+    # what the block-cache call here was working around. That also reached for
+    # output_components, which exists only under __main__ and so is undefined
+    # in the worker process that imports this module.
+    output = Path(mkdtemp(prefix="dexter-")) / "performance.mid"
+    try:
+        render(source, output, int(seed))
+    except Exception as exc:
+        raise gr.Error(f"DExter inference failed: {exc}") from exc
+
+    return str(output)
 
 
 if __name__ == "__main__":