SIFR-FLOW-0003: Invalid nonlocal or nested-function flow. - Sifr

SIFR-FLOW-0003 belongs to the Control flow diagnostic family. It means: invalid nonlocal or nested-function flow.

Why It Happens

The control-flow graph cannot satisfy Sifr’s static rules. Repair unsupported statements, invalid loop control, non-boolean conditions, missing returns, or unreachable code.

Use sifr --explain SIFR-FLOW-0003 locally to see the renderer’s exact message template and any machine-applicable suggestions for the compiler version you are running.

Erroneous Code

def label(value: int) -> str:
    if value > 0:
        return "positive"

How To Fix It

Repair the control-flow shape: put break/continue inside loops, return on every required path, and use supported loop and assignment forms.

Fixed Code

def label(value: int) -> str:
    if value > 0:
        return "positive"
    return "zero or negative"

Details

Field	Value
Code	`SIFR-FLOW-0003`
Family	`FLOW`
Severity	Error
Stability	stable
Owner	`sifr_lowering::lower`
Representative fixture	`crates/sifr/tests/e2e/fail/nested_function_recursive_nonlocal_unsupported.sifr`

See the Error Codes index for the complete catalog.