zzstoatzz.io
prefect server in zig
fix benchmark harness to capture server errors without blocking
- use DEVNULL during normal benchmark runs to avoid pipe buffer deadlock
- on startup failure, restart with PIPE to capture error output
- display actual error message instead of generic "failed to start server"
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
+1
-1
loq.toml
+1
-1
loq.toml
+21
-1
scripts/benchmark
+21
-1
scripts/benchmark
···
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self.broker_backend = broker_backend
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self.process: subprocess.Popen | None = None
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self.project_root = Path(__file__).parent.parent
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+
self.startup_error: str | None = None
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def start(self) -> bool:
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"""Start the server."""
···
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if self.db_backend == "postgres":
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env.setdefault("PREFECT_DATABASE_URL", "postgresql://prefect:prefect@localhost:5432/prefect")
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# first attempt: DEVNULL to avoid buffer issues during benchmark
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self.process = subprocess.Popen(
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[str(binary)],
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cwd=self.project_root,
···
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)
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if not wait_for_health():
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self.stop()
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# restart with output capture to get error message
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self.process = subprocess.Popen(
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[str(binary)],
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cwd=self.project_root,
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env=env,
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stdout=subprocess.PIPE,
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stderr=subprocess.STDOUT,
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text=True,
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)
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time.sleep(2) # give server time to fail
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if self.process.poll() is not None:
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output, _ = self.process.communicate()
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self.startup_error = output.strip()[-500:] if output else "server exited"
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else:
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self.startup_error = "health check timeout"
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self.stop()
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return False
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return True
···
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manager = ServerManager(server_type, db_backend, broker_backend)
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if not manager.start():
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console.print("[red]failed[/red]")
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if manager.startup_error:
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console.print(f"[dim]{manager.startup_error}[/dim]")
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return BenchmarkResult(
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server=server_type,
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success=False,
···
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endpoints=[],
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db_backend=db_backend,
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broker_backend=broker_backend,
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-
error="failed to start server",
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error=manager.startup_error or "failed to start server",
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)
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console.print("running benchmark...", end=" ")