JSONRPC Server Connection Failure Due to Stdout Contamination

[eleanorjboyd]

Summary

The JSONRPC server breaks after commit 2df70d1 due to tracing output being written to stdout, corrupting the JSONRPC protocol communication and causing connection errors in client extensions.

Environment

• Affected versions: Builds after commit 2df70d1
• Platform: All platforms (macOS, Windows, Linux)

Symptoms

• Extension UI (e.g., py-envs) shows endless loading state
• Console error: Connection Error: [{},null,null]
• JSONRPC communication fails completely
• Server appears to hang or not respond to requests

Root Cause

Commit 2df70d1 introduced performance tracing via tracing-subscriber. The tracing configuration writes log/trace output to stdout by default, but the JSONRPC server communicates via stdin/stdout. This causes log messages to intermix with JSONRPC messages, corrupting the protocol.

Solution

Redirect all tracing output to stderr by adding .with_writer(std::io::stderr) to the tracing subscriber configuration.

[eleanorjboyd]

closed by #340