elastic/elasticsearch · error · InvalidUserDataException

Parsing signatures failed: {}

Error message

Parsing signatures failed: {}

What it means

Thrown when the forbidden-apis checker raises a ParseException while parsing a signatures file or the joined inline signatures string. The signature syntax is invalid (malformed method/field signature), so the checker cannot build its rule set. This is a user-data error in the signature definition, distinct from [243] which is an IO fault.

Source

Thrown at build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/precommit/CheckForbiddenApisTask.java:519

                        }
                    }

                    final FileCollection signaturesFiles = getParameters().getSignaturesFiles();
                    if (signaturesFiles != null) for (final File f : signaturesFiles) {
                        checker.parseSignaturesFile(f);
                    }
                    final List<String> signatures = getParameters().getSignatures().get();
                    if ((signatures != null) && !signatures.isEmpty()) {
                        final StringBuilder sb = new StringBuilder();
                        for (String line : signatures) {
                            sb.append(line).append(NL);
                        }
                        checker.parseSignaturesString(sb.toString());
                    }
                } catch (IOException ioe) {
                    throw new GradleException("IO problem while reading files with API signatures.", ioe);
                } catch (ParseException pe) {
                    throw new InvalidUserDataException("Parsing signatures failed: " + pe.getMessage(), pe);
                }

                if (checker.hasNoSignatures()) {
                    if (checker.noSignaturesFilesParsed()) {
                        throw new InvalidUserDataException(
                            "No signatures were added to task; use properties 'signatures', 'bundledSignatures', 'signaturesURLs', and/or 'signaturesFiles' to define those!"
                        );
                    } else {
                        logger.info("Skipping execution because no API signatures are available.");
                        return;
                    }
                }

                try {
                    checker.addClassesToCheck(getParameters().getClassFiles());
                } catch (IOException ioe) {
                    throw new GradleException("Failed to load one of the given class files.", ioe);
                }

View on GitHub (pinned to db6a809a66)

Solutions

1. Read pe.getMessage() in the stack trace — it names the offending signature and the parse position.
2. Open the cited signatures file/line and correct the signature to the form ClassName#methodName(descriptor) or ClassName#fieldName.
3. Validate against the forbidden-apis documentation for the bundled version.
4. Re-run the single task to confirm parsing succeeds.

Example fix

// before (broken)
java.lang.String#substring(int,int) typo

// after
java.lang.String#substring(int,int)

// Lint signature lines against the forbidden-apis grammar before passing them
for (String line : signatures) {
    String s = line.trim();
    if (s.isEmpty() || s.startsWith("#") || s.startsWith("@")) continue;
    if (!s.matches("[\\w.$]+(#\\w+(\\([^)]*\))?|#\\w+|\\s+.*).*")) {
        throw new InvalidUserDataException("Malformed signature: " + s);
    }
}

try {
    checker.parseSignaturesString(joined);
} catch (InvalidUserDataException e) {
    // e.getCause() is the ParseException; its message names the bad token
    throw e;
}

When it happens

Trigger: A signature line that does not match the forbidden-apis signature grammar (e.g. missing class@method form, wrong descriptor syntax, unparseable type), supplied via the 'signatures' property or a signatures file.

Common situations: Hand-written signature files with typos; copying a signature from a different forbidden-apis version with incompatible grammar; an inline signatures string with stray characters; upgrading the forbidden-apis dependency which changed signature syntax.

Related errors

• IO problem while reading files with API signatures.
• No signatures were added to task; use properties 'signatures
• Failed to load one of the given class files.
• Forbidden API verification failed
• Missing 'classesDirs' or 'classpath' property.

AI-assisted analysis of elastic/elasticsearch@db6a809a66 (2026-08-12). Data as JSON: /api/errors/4a11caf491b0c578. Report an issue: GitHub.