apache/maven · error · IllegalStateException

Extension with illegal version in file ${extensionFile}: ${g

Error message

Extension with illegal version in file ${extensionFile}: ${ga} defined on lines ${lineNumbers}

What it means

Error "Extension with illegal version in file ${extensionFile}: ${ga} defined on lines ${lineNumbers}" thrown in apache/maven.

Source

Thrown at impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/BaseParser.java:557

            String ga = coreExtension.getGroupId() + ":" + coreExtension.getArtifactId();
            InputLocation location = coreExtension.getLocation("");
            gasLocations.computeIfAbsent(ga, k -> new ArrayList<>()).add(location);
            // TODO: metaversions could be extensible enum with these two values out of the box
            if ("LATEST".equals(coreExtension.getVersion()) || "RELEASE".equals(coreExtension.getVersion())) {
                metaVersionLocations.computeIfAbsent(ga, k -> new ArrayList<>()).add(location);
            }
        }
        if (gasLocations.values().stream().anyMatch(l -> l.size() > 1)) {
            throw new IllegalStateException("Extension conflicts in file " + extensionFile + ": "
                    + gasLocations.entrySet().stream()
                            .map(e -> e.getKey() + " defined on lines "
                                    + e.getValue().stream()
                                            .map(l -> String.valueOf(l.getLineNumber()))
                                            .collect(Collectors.joining(", ")))
                            .collect(Collectors.joining("; ")));
        }
        if (!allowMetaVersions && !metaVersionLocations.isEmpty()) {
            throw new IllegalStateException("Extension with illegal version in file " + extensionFile + ": "
                    + metaVersionLocations.entrySet().stream()
                            .map(e -> e.getKey() + " defined on lines "
                                    + e.getValue().stream()
                                            .map(l -> String.valueOf(l.getLineNumber()))
                                            .collect(Collectors.joining(", ")))
                            .collect(Collectors.joining("; ")));
        }
        return coreExtensions;
    }

    @Nullable
    protected CIInfo detectCI(LocalContext context) {
        List<CIInfo> detected = CIDetectorHelper.detectCI();
        if (detected.isEmpty()) {
            return null;
        } else if (detected.size() > 1) {
            // warn
            context.parserRequest

View on GitHub (pinned to e4093d4e12)

When it happens

Trigger: Thrown at impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/BaseParser.java:557 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/maven@e4093d4e12 (2026-08-21). Data as JSON: /api/errors/d12824e3a7144abe. Report an issue: GitHub.