github/copilot-sdk · error · IOException

Invalid runtime asset mode in

Error message

Invalid runtime asset mode in 

What it means

Inventory lines encode the asset's file mode as an octal integer parsed with Integer.parseInt(fields[0], 8). If that field is not a valid octal number (e.g. '9xx', letters, empty), a NumberFormatException is caught and rethrown as this IOException naming the inventory resource. It signals a malformed or corrupted inventory file, not a problem with the local environment.

Solutions

1. Fix the inventory resource so every mode field is a valid octal literal (e.g. 644, 755).
2. Replace the corrupted/mismatched artifact jar with an intact official build.
3. If generating inventories yourself, write modes with Integer.toOctalString(mode) and parse with radix 8.

Example fix

// before (inventory line)
rwxr-xr-x bin/cli
// after
755 bin/cli

// Java: pre-scan inventory mode fields for octal validity before extraction
for (String line : inventoryLines) {
    String mode = line.split(" ", 2)[0];
    Integer.parseInt(mode, 8); // throws NumberFormatException on bad mode
}

try { loader.loadRuntime(); } catch (IOException e) { if (e.getMessage().startsWith("Invalid runtime asset mode in")) { // artifact is malformed: replace jar, do not retry } else throw e; }

When it happens

Trigger: An inventory line whose mode field cannot be parsed in base 8 — e.g. '999 file', '0x1ed file', 'rwx file', or an empty mode field.

Common situations: Hand-edited or tool-generated inventory using decimal or symbolic ('rwxr-xr-x') modes instead of octal; corrupted jar contents; a new inventory format written by a mismatched library version.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• Unexpected trailing content at position
• Unescaped control character at position <pos-1>
• Unterminated string escape at position
• Invalid escape sequence \
• Incomplete Unicode escape at position <pos-2>

AI-assisted analysis of github/copilot-sdk@cd8cf15dc3 (2026-09-09). Data as JSON: /api/errors/9316a2c49cddf3f3. Report an issue: GitHub.

Appendix: source

Thrown at java/sdk/src/main/java/com/github/copilot/ffi/NativeRuntimeLoader.java:489

                String resourcePath = "native/" + classifier + "/" + fields[1];
                URL resource = loader.getResource(resourcePath);
                if (resource == null) {
                    throw new FileNotFoundException("Runtime asset not found on classpath: " + resourcePath);
                }
                Files.createDirectories(cached.getParent());
                Path temp = Files.createTempFile(cached.getParent(), "runtime-asset-tmp-", "");
                try {
                    copyResourceToTemp(resource, resourcePath, temp);
                    if (executable) {
                        makeExecutable(temp);
                    }
                    publisher.publish(temp, cached);
                } finally {
                    tryDelete(temp);
                }
            }
        } catch (NumberFormatException ex) {
            throw new IOException("Invalid runtime asset mode in " + inventoryResourcePath, ex);
        }
    }

    /**
     * Extracts the copilot CLI executable from the classpath to the same cache
     * directory as {@code runtime.node}. Idempotent — skips extraction if already
     * present and valid.
     */
    static void extractCliToCache(Path cacheDir, ClassLoader loader, String classifier, AtomicPublisher publisher)
            throws IOException {
        String cliName = isWindows() ? CLI_FILENAME_WINDOWS : CLI_FILENAME;
        String cliResourcePath = "native/" + classifier + "/" + cliName;
        Path cachedCli = cacheDir.resolve(cliName);

        if (isValidCachedCli(cachedCli)) {
            return;
        }

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