rtd remove unshallow

[bjlittle]

🚀 Pull Request

Description

This PR resolves this issue on RTD building for main:

Which didn't present itself whilst testing on a private branch for #271.

Here is the successful build of the documentation for this pull-request.

Closes #267

[bjlittle]

@trexfeathers I can't quite explain this... don't quite understand why this issue didn't happen for #271 when testing.

[trexfeathers]

@trexfeathers I can't quite explain this... don't quite understand why this issue didn't happen for #271 when testing.

@bjlittle I also want to understand why it's not a problem for Iris - see iris/.readthedocs.yml#L8-10

[trexfeathers]

This could plausibly be down to a difference in config within RTD. I set up cf-units as bare-bones as I could, so perhaps Iris has a better config that we should be mimicking.

[bjlittle]

@trexfeathers I think it's a difference in the repos. iris has more history.

Also, it's clear that you do need to do git fetch --unshallow for iris otherwise the version is wrong.

[trexfeathers]

@bjlittle and I now understand that git fetch --unshallow is invalid for cf-units, because cf-units (unlike Iris) is NOT a shallow repository. This might change in future if anything 'nasty' happens in the Git history, but the aim/hope is that it remains unshallow.