Created attachment 225302 [details]
This morning's update of devel/glib20 to release 2.68.2 broke the build of open-vm-tools due to an API change.
The attached patch lets it build again, but I cannot say whether the patch is correct. Anything with the word "volatile" in it is scary.
Thanks for the report.
@nc please take a look at this, and consider to (read: do) request exp-runs in the future.
Keep for the future updates: upstream has own, more complete solution.