LYR-RT0020

the runtime found its own invariant broken

panic · spec 16-diagnostics

The runtime met a state its own rules exclude — a thread allocating that the collector does not know, an object whose descriptor gives no size, a pointer the collector's map of a type does not name, a young object stored without its barrier, a coroutine whose descriptor is no coroutine's. That is a bug in the runtime or in the compiler, never in the program.

Explanation

The collector and the coroutines check a few of their own invariants as they go, where breaking one would corrupt memory in silence. The panic names what was found; the program cannot cause it, whatever it does.

Report the program with the message and the trace.

Example

$ ./out/debug/x86_64-linux-gnu/app
panic[LYR-RT0020]: the map of app.Node does not name its word at offset 16, which points at an unmarked app.Leaf