jenkinsci/jenkins · warning · Failure

The name “{0}” is already in use.

Error message

The name “{0}” is already in use.

What it means

Thrown by checkIfNameIsUsed(newName) when a same-named item already exists in the parent and the current user can see it (getItem returns non-null without ACL elevation). The localized 'NewNameInUse' message tells the user the name is taken. This is the straightforward collision case — the rename would create a duplicate.

Source

Thrown at core/src/main/java/hudson/model/AbstractItem.java:312

            }
            Jenkins.get().getProjectNamingStrategy().checkName(getParent().getFullName(), newName);
            checkIfNameIsUsed(newName);
            checkRename(newName);
        } catch (Failure e) {
            return FormValidation.error(e.getMessage());
        }
        return FormValidation.ok();
    }

    /**
     * Check new name for job
     * @param newName - New name for job.
     */
    private void checkIfNameIsUsed(@NonNull String newName) throws Failure {
        try {
            Item item = getParent().getItem(newName);
            if (item != null) {
                throw new Failure(Messages.AbstractItem_NewNameInUse(newName));
            }
            try (ACLContext ctx = ACL.as2(ACL.SYSTEM2)) {
                item = getParent().getItem(newName);
                if (item != null) {
                    if (LOGGER.isLoggable(Level.FINE)) {
                        LOGGER.log(Level.FINE, "Unable to rename the job {0}: name {1} is already in use. " +
                                "User {2} has no {3} permission for existing job with the same name",
                                new Object[] {this.getFullName(), newName, ctx.getPreviousContext2().getAuthentication().getName(), Item.DISCOVER.name});
                    }
                    // Don't explicitly mention that there is another item with the same name.
                    throw new Failure(Messages.Jenkins_NotAllowedName(newName));
                }
            }
        } catch (AccessDeniedException ex) {
            if (LOGGER.isLoggable(Level.FINE)) {
                LOGGER.log(Level.FINE, "Unable to rename the job {0}: name {1} is already in use. " +
                        "User {2} has {3} permission, but no {4} for existing job with the same name",
                        new Object[] {this.getFullName(), newName, User.current(), Item.DISCOVER.name, Item.READ.name});

View on GitHub (pinned to 2e228ff40b)

Solutions

1. Choose a unique new name that does not exist in the same parent folder
2. Check for collisions before submitting: call getParent().getItem(newName) and validate
3. If the target item is one you intend to replace, delete or rename it first
4. Be aware of case-insensitive matching on Windows/macOS filesystems

Example fix

// before: rename blindly
item.renameTo(takenName);
// after: check first
if (item.getParent().getItem(takenName) != null) {
    throw new Failure("Name '" + takenName + "' is already in use");
}
item.renameTo(takenName);

if (item.getParent().getItem(newName) != null) {
    throw new IllegalStateException("Name '" + newName + "' already exists in parent");
}

try {
    // rename flow
} catch (Failure f) {
    if (f.getMessage().contains("already in use")) {
        // prompt user for a different name
    }
    throw f;
}

When it happens

Trigger: During a rename, checkIfNameIsUsed calls getParent().getItem(newName); if non-null (and visible to the caller), it throws Failure with AbstractItem_NewNameInUse.

Common situations: Renaming a job to a name that matches an existing job in the same folder; case-insensitive collisions on case-insensitive filesystems; automation scripts computing new names that clash.

Related errors

• Trying to rename an item that does not support this operatio
• New name is not given
• “{0}” is not an allowed name
• No ancestor of type {} in the request
• A logger named "{0}" does not exist. Add a logger by this na

AI-assisted analysis of jenkinsci/jenkins@2e228ff40b (2026-08-14). Data as JSON: /api/errors/e6154fd0754f282c. Report an issue: GitHub.