X_ERROR_RENDER_UNSAFE

an error factory builds its cause: or fix: from an unknown in a way that can throw

a parameter typed unknown/any reaching a message through bare ${value}, JSON.stringify(value) or String(value). All three throw on a real app value — JSON.stringify on a bigint or a cycle, and it runs any toJSON the value carries, so an app object can hijack the constructor and the caller catches something that is not the error the framework meant to raise. This shipped three separate times before it was mechanised

the fix names the <file>:<line> — wrap it: renderCauseValue(x) for a cause, which only has to describe, or renderFixLiteral(x, '<placeholder>') for a fix, which has to parse. Both from @ultimat3/core