Hardlinks cause problems

[Peter Suter]

Hi,

Many years ago in https://bz.mercurial-scm.org/show_bug.cgi?id=1922 
people recommended using "clone --pull" to avoid hardlinks.
This is also still recommended on 
https://www.mercurial-scm.org/wiki/HardlinkedClones and in top search 
results  like 
https://serverfault.com/questions/127440/how-to-tell-mercurial-to-never-create-hard-links

This has worked well for us so far, but recently we upgraded our 
Mercurial server, and now the "Azure Backup" fails. Apparently it does 
not support hardlinks: 
https://docs.microsoft.com/en-us/azure/backup/backup-support-matrix-mars-agent#supported-file-types-for-backup
 > Hard links Not supported.

But we do use "clone --pull", so we thought there were no hardlinks. 
Apparently Mercurial nowadays still uses hardlinks? The files that fails 
are mainly `.hg/undo.bookmarks` and similar files.

Is there a way to "fully" disable the use of hardlinks in Mercurial?
Alternatively: Is it save to just delete the `.hg/undo.*` files before 
we run the Azure Backup?

Thanks,
Peter