SH3005: The game's tool program didn't build, or stopped before it answered

Class: operation, exit code 1.

The MCP server (shuyi mcp) runs the game's tool program (shuyi.ron's game) with cargo run to answer a tool that runs the game, and keeps it running for the session. The program didn't build, or it stopped before it answered: a compile error, a panic in the game, or a game whose engine is older than the server's. The message ends with the last of its output.

A project in another cargo workspace than the server's (a worktree, say) is answered by the project's own MCP server, built from that workspace's engine: its command and mcp. When that server didn't build, or stopped, the message names it ("the project's own server") and ends with the last of its output: the compile error is in the engine or the game of that workspace.

How to fix it. Read the output in the message, fix the game's code (or its engine's version, or the workspace's engine), then call the tool again: the server builds it again. A session that was running has ended: call start again.

For example:

start: error[SH3005]: the game's tool program stopped before it answered (exit code 101): error[E0425]: cannot find value `hero` in this scope