{"record":{"id":"4e3bb816d2103465","repo":"testcontainers/testcontainers-java","slug":"the-org-testcontainers-namespace-is-reserved-for-internal","errorCode":null,"errorMessage":"The org.testcontainers namespace is reserved for internal use","messagePattern":"The org\\.testcontainers namespace is reserved for internal use","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"core/src/main/java/org/testcontainers/containers/GenericContainer.java","lineNumber":1118,"sourceCode":"        return self();\n    }\n\n    /**\n     * {@inheritDoc}\n     */\n    @Override\n    public SELF withEnv(Map<String, String> env) {\n        env.forEach(this.containerDef::addEnvVar);\n        return self();\n    }\n\n    /**\n     * {@inheritDoc}\n     */\n    @Override\n    public SELF withLabel(String key, String value) {\n        if (key.startsWith(\"org.testcontainers\")) {\n            throw new IllegalArgumentException(\"The org.testcontainers namespace is reserved for internal use\");\n        }\n        this.containerDef.addLabel(key, value);\n        return self();\n    }\n\n    /**\n     * {@inheritDoc}\n     */\n    @Override\n    public SELF withLabels(Map<String, String> labels) {\n        labels.forEach(this::withLabel);\n        return self();\n    }\n\n    /**\n     * {@inheritDoc}\n     */\n    @Override","sourceCodeStart":1100,"sourceCodeEnd":1136,"githubUrl":"https://github.com/testcontainers/testcontainers-java/blob/8e549514e3f01c57d70546fbb8599d138f3903e5/core/src/main/java/org/testcontainers/containers/GenericContainer.java#L1100-L1136","documentation":"Generic guard in GenericContainer.withLabel: any label key beginning with the reserved 'org.testcontainers' prefix is rejected with IllegalArgumentException, because Testcontainers uses that namespace for internal metadata. The at-fault input is a user-supplied label key under that reserved prefix.","triggerScenarios":"Thrown at core/src/main/java/org/testcontainers/containers/GenericContainer.java:1118 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Use a label key that does not start with 'org.testcontainers'","Use your own namespace, e.g. 'com.mycompany.mylabel'"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"8e549514e3f01c57d70546fbb8599d138f3903e5","analyzedAt":"2026-09-12T14:56:41.227Z","contentChangedAt":"2026-09-12T14:56:41.227Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}