generate-image: --prompt (or --prompt-file) and --out are re

Error message

generate-image: --prompt (or --prompt-file) and --out are required.

What it means

Required-argument guard in generate-image's fake mode (IMPECCABLE_IMAGE_GEN_FAKE set): the let-else on (Some(prompt), Some(out)) fails when the prompt — taken from --prompt-file contents or --prompt — is missing/empty, or --out was not passed.

Source

Thrown at crates/context/src/generate_image.rs:257

        match std::fs::read(abs(pf)) {
            Ok(b) => Ok(String::from_utf8_lossy(&b).into_owned()),
            Err(e) => {
                io.err(&format!("Error: {}\n", node_read_error(pf, &e)));
                Err(1)
            }
        }
    };
    if env.get("IMPECCABLE_IMAGE_GEN_FAKE").map(|v| !v.is_empty()).unwrap_or(false) {
        let prompt = match arg(args, "prompt-file") {
            Some(pf) => match read_prompt_file(io, &pf) {
                Ok(p) => Some(p),
                Err(c) => return c,
            },
            None => arg(args, "prompt"),
        };
        let out = arg(args, "out");
        let (Some(prompt), Some(out)) = (prompt.filter(|p| !p.is_empty()), out) else {
            io.err("generate-image: --prompt (or --prompt-file) and --out are required.\n");
            return 1;
        };
        let (w, h) = parse_size(&arg(args, "size").unwrap_or_else(|| "1536x1024".into()));
        let bytes = if out.ends_with(".svg") { svg_fake(&prompt, w as f64, h as f64).into_bytes() } else { png_fake(&prompt, w, h) };
        if let Err(e) = std::fs::write(abs(&out), bytes) {
            io.err(&format!("Error: {}\n", node_read_error(&out, &e)));
            return 1;
        }
        io.out(&format!("IMAGE: {} ({}x{}, fake synthetic comp, $0.00, no API call)\n", out, w, h));
        return 0;
    }
    let Some(key) = env.get("OPENAI_API_KEY").filter(|k| !k.is_empty()).cloned() else {
        io.err("generate-image: OPENAI_API_KEY is not set; use the harness-native image tool instead.\n");
        return 1;
    };
    let prompt = match arg(args, "prompt-file") {
        Some(pf) => match read_prompt_file(io, &pf) {
            Ok(p) => Some(p),

View on GitHub (pinned to 2bc2879276)

Solutions

Provide both flags: `impeccable generate-image --prompt "..." --out out.png`.
Guard empty prompt variables in scripts before invoking.
Ensure --out points to a writable destination path.

Example fix

// before
impeccable generate-image --prompt "a cat"
// after
impeccable generate-image --prompt "a cat" --out out.png

Defensive patterns

Strategy: validation

Validate before calling

[ -n "$PROMPT" ] && [ -n "$OUT" ] || { echo "--prompt and --out are required" >&2; exit 1; }

Type guard

const canGenerate = (args) => Boolean(args.out && args.prompt && args.prompt.trim().length > 0);

Prevention

Always pass both --prompt (or --prompt-file) and --out
Guard required shell variables before invocation
Wrap generate-image calls in a script function that checks arguments

When it happens

Trigger: Running `impeccable generate-image` without --out, without --prompt/--prompt-file, or with an empty --prompt value.

Common situations: Forgot --out while testing interactively, empty shell variable for the prompt, or a script building the command dropped empty arguments.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of pbakaus/impeccable@2bc2879276 (2026-09-08). Data as JSON: /api/errors/f4f708af3384aa09. Report an issue: GitHub.