SIFR-IO-0801: Text-mode open requires an explicit encoding. - Sifr

SIFR-IO-0801 belongs to the File and stream I/O diagnostic family. It means: text-mode open requires an explicit encoding.

Why It Happens

Sifr makes file mode and text encoding boundaries explicit. This diagnostic fires when file I/O would cross those boundaries unsafely or ambiguously.

Use sifr --explain SIFR-IO-0801 locally to see the renderer’s exact message template and any machine-applicable suggestions for the compiler version you are running.

Erroneous Code

from sifr.io import open

file = open("notes.txt", "r")

How To Fix It

Make file modes and encodings explicit at compile time, especially at text/binary boundaries.

Fixed Code

from sifr.io import open_text

file = open_text("notes.txt", encoding="utf-8")

Details

Field	Value
Code	`SIFR-IO-0801`
Family	`IO`
Severity	Error
Stability	stable
Owner	`sifr_lowering::lower::expressions::call_shadowable_builtins`
Representative fixture	`crates/sifr/tests/e2e/fail/text_i18n_open_without_encoding.sifr`

See the Error Codes index for the complete catalog.