print any collected debug output when returning a timeout error

nominatim/server/falcon/server.py

@@ -16,6 +16,7 @@
 
 from nominatim.api import NominatimAPIAsync
 import nominatim.api.v1 as api_impl
+import nominatim.api.logging as loglib
 from nominatim.config import Configuration
 
 class HTTPNominatimError(Exception):
@@ -45,8 +46,15 @@ async def timeout_error_handler(req: Request, resp: Response, #pylint: disable=u
         per exception info.
     """
     resp.status = 503
-    resp.text = "Query took too long to process."
-    resp.content_type = 'text/plain; charset=utf-8'
+
+    loglib.log().comment('Aborted: Query took too long to process.')
+    logdata = loglib.get_and_disable()
+    if logdata:
+        resp.text = logdata
+        resp.content_type = 'text/html; charset=utf-8'
+    else:
+        resp.text = "Query took too long to process."
+        resp.content_type = 'text/plain; charset=utf-8'
 
 
 class ParamWrapper(api_impl.ASGIAdaptor):

nominatim/server/starlette/server.py

@@ -15,14 +15,15 @@
 from starlette.applications import Starlette
 from starlette.routing import Route
 from starlette.exceptions import HTTPException
-from starlette.responses import Response, PlainTextResponse
+from starlette.responses import Response, PlainTextResponse, HTMLResponse
 from starlette.requests import Request
 from starlette.middleware import Middleware
 from starlette.middleware.base import BaseHTTPMiddleware, RequestResponseEndpoint
 from starlette.middleware.cors import CORSMiddleware
 
 from nominatim.api import NominatimAPIAsync
 import nominatim.api.v1 as api_impl
+import nominatim.api.logging as loglib
 from nominatim.config import Configuration
 
 class ParamWrapper(api_impl.ASGIAdaptor):
@@ -115,6 +116,12 @@ async def timeout_error(request: Request, #pylint: disable=unused-argument
                         _: Exception) -> Response:
     """ Error handler for query timeouts.
     """
+    loglib.log().comment('Aborted: Query took too long to process.')
+    logdata = loglib.get_and_disable()
+
+    if logdata:
+        return HTMLResponse(logdata)
+
     return PlainTextResponse("Query took too long to process.", status_code=503)