How to use metal ICBs properly?

[jinleili]

I implemented RenderBundle very roughly using ICB and could only run the msaa-line example:
jinleili@6dce2b8

Using ICBs, MTLRenderPipelineDescriptor must set supportIndirectCommandBuffers to TRUE, but when this reusable pipeline used on normal draw call will cause error:

Internal error in VERTEX | FRAGMENT | VERTEX_FRAGMENT shader: new_render_pipeline_state: "Fragment shader cannot be used with indirect command buffers"

I don't know how to do it properly，is recreate pipeline object inside RenderBundle achievable and acceptable?