Five real MCP tool call failure modes for MemNexus — server not appearing, auth errors, timeouts, stale schemas after upgrades, empty search results — with the exact commands to diagnose and fix each one.
We nearly shipped a P0 fix for what looked like a PostHog bot filter false positive — until we read the source and found the filter working exactly as designed. Here's the real check order, and the test we built instead.
How the MemNexus team diagnosed a recurring CI failure pattern across 5 incidents in 10 days — and why the sixth incident took 2 minutes instead of 2 hours.
Most developers debug the same classes of bugs repeatedly. Here's a workflow that uses persistent memory to make each debugging session faster than the last.