# `ExMujoco.Error`
[🔗](https://github.com/d-led/ex.mujoco/blob/main/lib/ex_mujoco/error.ex#L1)

What MuJoCo says when it refuses.

MuJoCo reports a fatal error by printing a message and not returning; inside a
NIF that would abort the VM. `c_src/mj_call.hpp` intercepts it and re-throws it
on the Elixir side, where it arrives as this exception — the message is
MuJoCo's own, with the function that raised it in front of it
(`mj_step: qpos is not finite`).

A `RuntimeError` escaping from `ExMujoco.Native` is the same thing before
`ExMujoco` has re-raised it; call the typed functions instead.

# `t`

```elixir
@type t() :: %ExMujoco.Error{__exception__: term(), message: String.t()}
```

MuJoCo's message, with the function that raised it in front of it.

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*Consult [api-reference.md](api-reference.md) for complete listing*