SH0005: The JSON Pointer names no value in the scene's data

Class: usage, exit code 2.

scene --path <pointer> (MCP's session scene with path) reads one value of the scene's data by JSON Pointer (RFC 6901): /hero/x is the key x of the key hero, /units/3 the fourth item of units, and /outcome/Won/turn the turn of an outcome that is Won. The pointer named a key the data doesn't have, an item past the end of a list, or went into a number or a string; or it was no pointer at all (one is empty, or starts with /). The message names the pointer and the keys of the deepest object it reached.

A key the game's data holds only some of the time is missing then: /outcome/Won names nothing while the stage is still played (its outcome is null), or after it was lost.

How to fix it. Pass a pointer to one of the keys the message lists. scene --json shows the whole data, and scene --shape its JSON Schema: every key it may hold. A / or a ~ in a key is written ~1 or ~0.

For example:

scene: error[SH0005]: no value at `/hero/z`: /hero has the keys x, y