clearcase ucm to git

I have a requirement to migrate a UCM VOB with multiple components to GitHub.

I have read many such questions and answers and I am also convinced that migrating all history is not worth the effort.

But, I still have been asked to do so. How do I go about it?
Or rather: where to start from where I could capture at least some meaningful history?

The general rules for an UCM import is:

• one Git repo per UCM component
• one main Git repo referencing those sub-repos as submodules

Then:

• Pick a stream.
• For each component, list their baselines.
• for each baseline, set your config spec and add its content to a Git repo, as shown here.

If your stream manages multiple component, and has set composite baselines (a baseline referencing other baselines), you can put a tag on the main repo (the one which refers the other git repos as submodules): that will help keep multiple Git repos history together.

The point is: only an UCM baseline is part of a meaningful history, as it represent a group of files in a coherent state (version), all labelled together.