jenkinsci/jenkins · error · IllegalArgumentException

Unknown ItemGroup

Error message

Unknown ItemGroup 

What it means

`CreateJobCommand.run()`: when NAME contains '/', the prefix before the last '/' is the parent ItemGroup. If `h.getItemByFullName(group)` returns null, IllegalArgumentException 'Unknown ItemGroup <group>' is thrown. The parent group must already exist (CreateJobCommand does not create intermediate folders).

Source

Thrown at core/src/main/java/hudson/cli/CreateJobCommand.java:64

    @Argument(metaVar = "NAME", usage = "Name of the job to create", required = true)
    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility")
    public String name;

    @Override
    protected int run() throws Exception {
        Jenkins h = Jenkins.get();

        if (h.getItemByFullName(name) != null) {
            throw new IllegalStateException("Job '" + name + "' already exists");
        }

        ModifiableTopLevelItemGroup ig = h;
        int i = name.lastIndexOf('/');
        if (i > 0) {
            String group = name.substring(0, i);
            Item item = h.getItemByFullName(group);
            if (item == null) {
                throw new IllegalArgumentException("Unknown ItemGroup " + group);
            }

            if (item instanceof ModifiableTopLevelItemGroup) {
                ig = (ModifiableTopLevelItemGroup) item;
            } else {
                throw new IllegalStateException("Can't create job from CLI in " + group);
            }
            name = name.substring(i + 1);
        }

        Jenkins.checkGoodName(name);
        ig.createProjectFromXML(name, stdin);
        return 0;
    }
}

View on GitHub (pinned to 2e228ff40b)

Solutions

1. Create the parent Folder first (Folders plugin), then create the job inside it.
2. Correct the folder name in the argument.
3. Create the job at top level (no '/') if nesting isn't needed.

Example fix

// before:
//   java -jar jenkins-cli.jar create-job misspelled/newjob < config.xml
//   -> IllegalArgumentException: Unknown ItemGroup misspelled
//
// after: create/verify the folder, then the job
//   java -jar jenkins-cli.jar create-job services < folder.xml
//   java -jar jenkins-cli.jar create-job services/newjob < config.xml

// Verify parent group exists for nested names
int i = name.lastIndexOf('/');
if (i > 0) {
    String group = name.substring(0, i);
    if (h.getItemByFullName(group) == null)
        throw new IllegalArgumentException("Unknown ItemGroup " + group);
}

When it happens

Trigger: Running `create-job myfolder/newjob < config.xml` where 'myfolder' is not an existing item.

Common situations: Typo in the folder portion; assuming folders are auto-created; missing an intermediate parent in a deep path.

Related errors

• Can't create job from CLI in
• Unknown ItemGroup
• Can't create job from CLI in
• Job ' already exists
• Job ' already exists

AI-assisted analysis of jenkinsci/jenkins@2e228ff40b (2026-08-14). Data as JSON: /api/errors/422b0050842992da. Report an issue: GitHub.