angular/angular-cli · error

A builder is not set for target '${target}' in project '${pr

Error message

A builder is not set for target '${target}' in project '${project}'.

What it means

Once the target is found, `findProjectTarget` requires `targetDefinition.builder` to be set, since the architect host must resolve a builder implementation. This throws when a target exists in angular.json but has no `builder` property (or an empty one), which can only happen with hand-edited or programmatically built workspace definitions.

Source

Thrown at packages/angular_devkit/architect/node/node-modules-architect-host.ts:59

}

function findProjectTarget(
  workspace: workspaces.WorkspaceDefinition,
  project: string,
  target: string,
): workspaces.TargetDefinition {
  const projectDefinition = workspace.projects.get(project);
  if (!projectDefinition) {
    throw new Error(`Project "${project}" does not exist.`);
  }

  const targetDefinition = projectDefinition.targets.get(target);
  if (!targetDefinition) {
    throw new Error('Project target does not exist.');
  }

  if (!targetDefinition.builder) {
    throw new Error(`A builder is not set for target '${target}' in project '${project}'.`);
  }

  return targetDefinition;
}

export class WorkspaceNodeModulesArchitectHost implements ArchitectHost<NodeModulesBuilderInfo> {
  private workspaceHost: WorkspaceHost;

  constructor(workspaceHost: WorkspaceHost, _root: string);

  constructor(workspace: workspaces.WorkspaceDefinition, _root: string);

  constructor(
    workspaceOrHost: workspaces.WorkspaceDefinition | WorkspaceHost,
    protected _root: string,
  ) {
    if ('getBuilderName' in workspaceOrHost) {
      this.workspaceHost = workspaceOrHost;

View on GitHub (pinned to bb72145f9a)

Solutions

1. Add the `builder` property to the target in angular.json (e.g. `"builder": "@angular-devkit/build-angular:application"`).
2. Restore the target block from version control or regenerate it with `ng generate` / `ng add` of the relevant package.
3. Install the package providing the builder if the field references a missing dependency (also check spelling of the builder string).
4. In programmatic use, set `targets.set(name, { builder, ... })` before invoking the architect host.

Example fix

// before
"my-target": {
  "options": {}
}
// after
"my-target": {
  "builder": "@angular-devkit/build-angular:application",
  "options": {}
}

const cfg = JSON.parse(fs.readFileSync('angular.json', 'utf8'));
for (const [name, t] of Object.entries<any>(cfg.projects?.[project]?.architect ?? {})) {
  if (!t.builder) throw new Error(`Target "${name}" in project "${project}" is missing "builder".`);
}

function hasBuilder(t: unknown): t is { builder: string; options?: object } {
  return typeof t === 'object' && t !== null && typeof (t as any).builder === 'string' && (t as any).builder.length > 0;
}

try {
  await architect.schedule(target, options, context);
} catch (e) {
  if ((e as Error).message.includes('A builder is not set for target')) {
    console.error('Add a "builder" field to the angular.json target:', (e as Error).message);
  } else { throw e; }
}

When it happens

Trigger: angular.json contains a target object missing the `builder` key, e.g. `{ "my-target": { "options": {} } }` with no `"builder": "@angular-devkit/build-angular:..."` string; or code constructing TargetDefinition without a builder.

Common situations: Manual edits to angular.json; partial copy-paste of target blocks; migration tools stripping builder fields; custom schematic output that omits builder; renaming a builder package without updating the field.

Related errors

• Project "${project}" does not exist.
• Project target does not exist.
• Cannot determine project for command. This is a multi-projec
• The builder requires a target.
• Could not find ${level} workspace.

AI-assisted analysis of angular/angular-cli@bb72145f9a (2026-08-30). Data as JSON: /api/errors/6513693039253f9c. Report an issue: GitHub.