---
name: general fatal errors
---
# General fatal errors

Runtime `die`s that are neither regex-compilation nor
compile-time syntax errors: method resolution, inheritance,
subroutine calls, attributes, and module-level usage errors. All
are fatal (**F**) and trappable with `eval` or `try`.

## Subroutine calls

### `` `Undefined subroutine &%s called` ``

**(F)** A call named a subroutine that does not exist at call
time. The fully-qualified name is shown. Causes: a typo in the
name, a missing `use` of the module that defines it, or calling
before the `sub` is declared in a context where that matters. The
runtime form `` `Undefined subroutine &NAME called at FILE line
N.` `` adds the call site.

## Method resolution and inheritance

### `` `Can't use anonymous symbol table for method lookup` ``

**(F)** Method dispatch reached a package with no named symbol
table (an anonymous stash). A blessed reference must point into a
real, named package for method calls to resolve.

### `` `Recursive inheritance detected in package '%s'` ``

**(F)** A class's `@ISA` chain leads back to itself - a cycle.
Method resolution cannot proceed. Break the loop in the
inheritance graph.

### `` `Inconsistent hierarchy during C3 merge of class '%s'` ``

**(F)** Under the C3 method-resolution order, the linearization of
this class's parents has no consistent ordering. Two parents
disagree on the order of a shared ancestor. Restructure the
inheritance so the parent orderings are compatible, or switch the
class back to the default depth-first MRO.

### `` `Invalid mro name: '%s'` ``

**(F)** A `use mro '...'` named an order that does not exist. The
two valid names are `` `dfs` `` (the default depth-first order)
and `` `c3` ``.

## Attributes

### `` `Unterminated attribute parameter in attribute list` ``

**(F)** An attribute with a parenthesized parameter -
`:Foo(bar` - was not closed. Balance the parentheses in the
attribute list.

## Module usage errors

These come from native modules when called incorrectly. They are
fatal because the call cannot proceed.

### `` `Usage: POSIX::sprintf(pattern, args...)` ``

**(F)** A `POSIX` function was called with the wrong arguments.
The message names the correct calling form.

### `` `IO::Socket::%s` ``

**(F)** An `IO::Socket` operation failed; the message names the
specific call.

## See also

- [`@ISA`](../perlvar) - the inheritance array whose contents the
  MRO errors are about.
- [`mro`](../../mro) - selecting and inspecting the
  method-resolution order.
- [`bless`](../perlfunc/bless) - associates a reference with the
  package whose methods the anonymous-symbol-table error is about.
- [Value and type errors](value-and-types) - "Not a subroutine
  reference" and the other what-kind-of-value diagnostics.