Diagnostics
Compiler/runtime diagnostic shape, known v12 error identifiers, common causes and scope limits.
01 diagnostic shape§
TypeError: expected int, found str
--> main.dby:1:14The supplied hosted language spec promises category, message, file path, line and column.
02 runtime overflow§
RuntimeError: integer overflow03 v12 generic recursion§
E_GENERIC_INSTANTIATION_RECURSIONThis is the one explicit v12 diagnostic identifier named in the normative contract: recursively growing generic type arguments must fail rather than instantiate without bound.
04 common failure map§
| Symptom | Likely contract cause | Action |
|---|---|---|
| use after move | non-Copy value already moved | borrow it, restructure ownership, or avoid the second use |
| mutable borrow rejected | exclusive borrow overlaps owner/another borrow | shorten lexical borrow scope |
| ptr conversion rejected | reverse const_ptr → ptr or non-usize integer conversion | use permitted pointer direction and explicit usize conversion |
| match rejected | non-exhaustive patterns or unsupported guards | cover variants or add _; v12 has no guards |
? rejected | operand is not canonical Result or error TypeId differs | return the identical Result error type |
| native intrinsic rejected | hosted/user profile cannot use privileged native.* | select the kernel profile or remove privileged operation |
05 what is NOT documented§
The supplied release material does not define a complete stable numeric/error-code catalog. This page therefore does not invent codes for every checker failure.
SOURCE POLICY: release/tag documents define contracts; examples are copied from the supplied v12.0.0 package or explicitly marked as explanatory. Unsupported claims are not upgraded by prose.