ui5-tooling: CF deploy fails with manifest.json not found

Expected Behavior

Deploy to CF is successful

Current Behavior

Deploy to CF fails with the tooling 3.0.0 with

[ERROR] Upload application content failed { CODE: '1001' } validation error: manifest.json not found

using fiori cfDeploy to deploy.

• the project was using tooling ver 2.14.17
• build script was: ui5 build preload --clean-dest --include-task=generateManifestBundle ....
• build script now adapted to 3.0.0 is: ui5 build preload --clean-dest .... - just this task removed according to 07a5be2
• no other changes introduced in the project

Project type is library. Do we miss other required adaptation for tooling 3.0.0?