What causes "comp-spec: no spec at {spec_path} " in pbakaus/impeccable?

Generate the spec first with `comp-spec --comp --regions `.

comp-spec: no spec at {spec_path}

Error message

comp-spec: no spec at {spec_path}

What it means

`comp-spec --plate-prompt <id>` first loads the spec (load_spec) before looking up the requested region. If the spec file cannot be loaded, it emits this shorter variant of the missing-spec message (without the how-to-fix hint) and exits 1. This error is about the spec store, not about the region id.

Source

Thrown at crates/comp-verbs/src/comp_spec.rs:809

/// `impeccable comp-spec ...`
pub fn run(argv: &[String], io: &mut Io) -> i32 {
    let spec_path = arg_or(argv, "spec", SPEC_PATH).to_string();
    if flag(argv, "help") || argv.is_empty() {
        io.out("usage: comp-spec.mjs --comp <png> --grid            write .impeccable/build/comp-grid.png (10x10 labeled grid) + palette + bands\n       comp-spec.mjs --comp <png> --regions <json>  measure regions -> .impeccable/build/spec.json\n         regions json: { \"regions\": [ { \"id\": \"art\", \"kind\": \"plate|image|texture|text|control|chrome\", \"grid\": \"E0:J4\", \"note\": \"...\" } ] }\n       comp-spec.mjs --comp <png> --auto            band regions when you have no regions file\n       comp-spec.mjs --print                        the compact spec\n       comp-spec.mjs --crop <id> [--out f] [--scale n]   reference crop of a region (never a shipping asset)\n       comp-spec.mjs --plate-prompt <id>            the regeneration prompt for a raster region\n");
        return 0;
    }
    if flag(argv, "print") {
        let Some(spec) = load_spec(&resolve(io, &spec_path)) else {
            io.err(&format!("comp-spec: no spec at {spec_path}; run with --comp <png> --regions <json> first\n"));
            return 1;
        };
        io.out(&format!("{}\n", print_spec(&spec)));
        return 0;
    }
    if let Some(id) = arg(argv, "plate-prompt") {
        let Some(spec) = load_spec(&resolve(io, &spec_path)) else {
            io.err(&format!("comp-spec: no spec at {spec_path}\n"));
            return 1;
        };
        let region = spec.get("regions").and_then(Value::as_array).and_then(|a| a.iter().find(|r| r.get("id").and_then(Value::as_str) == Some(id)));
        let Some(region) = region else {
            io.err(&format!("comp-spec: no region {id}\n"));
            return 1;
        };
        io.out(&format!("{}\n", plate_prompt(&spec, region)));
        return 0;
    }
    if let Some(id) = arg(argv, "crop") {
        let Some(spec) = load_spec(&resolve(io, &spec_path)) else {
            io.err(&format!("comp-spec: no spec at {spec_path}\n"));
            return 1;
        };
        let region = spec.get("regions").and_then(Value::as_array).and_then(|a| a.iter().find(|r| r.get("id").and_then(Value::as_str) == Some(id))).cloned();
        let Some(region) = region else {
            let ids = spec.get("regions").and_then(Value::as_array).map(|a| a.iter().filter_map(|r| r.get("id").and_then(Value::as_str)).collect::<Vec<_>>().join(", ")).unwrap_or_default();

View on GitHub (pinned to 2bc2879276)

Solutions

Generate the spec first with `comp-spec --comp <png> --regions <json>`.
Verify the spec path — pass explicit --spec if not using the default .impeccable/build/spec.json.
Re-run from the correct working directory.

Example fix

// before
$ impeccable comp-spec --plate-prompt art
comp-spec: no spec at .impeccable/build/spec.json
// after
$ impeccable comp-spec --comp ./comp.png --regions ./regions.json
$ impeccable comp-spec --plate-prompt art

Defensive patterns

Strategy: validation

Validate before calling

import { existsSync } from 'node:fs';
const specPath = args.spec ?? '.impeccable/build/spec.json';
if (!existsSync(specPath)) throw new Error(`spec missing at ${specPath}; generate before --plate-prompt`);

Try / catch

const r = spawnSync('impeccable', ['comp-spec', '--plate-prompt', id]);
if (r.status === 1 && /no spec at/.test(r.stderr.toString())) {
  runSync('impeccable', ['comp-spec', '--comp', comp, '--regions', regions]);
  // then retry the plate-prompt call
}

Prevention

Run comp-spec measure mode before any --plate-prompt usage.
In CI, restore or regenerate the spec at job start.
Pass an explicit --spec path when operating outside the default build dir.

When it happens

Trigger: Running `comp-spec --plate-prompt <id>` when no spec exists at spec_path (never generated, deleted, or wrong --spec path / working directory).

Common situations: Same as --print: cleaned build dir, wrong cwd, typo'd --spec path; also automation invoking --plate-prompt before the measure step ran in a fresh CI workspace.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

AI-assisted analysis of pbakaus/impeccable@2bc2879276 (2026-09-08). Data as JSON: /api/errors/8c9979b6e63d022d. Report an issue: GitHub.