Found this project. It mentions several shortcomings of Coarray.
I am not too familiar with coarrays, but this page dates back to 2009-2011. I think some of the mentioned shortcomings like collective subroutines and process subsets (teams) were added in Fortran 2018.
Edit: a good resource on this topic is the book from Milan Curcic (@curcic).
I am quite enjoying coarrays. In a sense, they feel much better to use than MPI. I know of Milan’s book, and am actually experimenting with events right now.
Have others been messing around with events and teams and collectives? Do you folks have any general thoughts, such as desired functionality, tips and tricks or implementation statuses/caveats on various compilers?
For example, it appears sync memory is not working on gfortran or intel. The event post and waits seem good for syncing in certain situations [I just used it for some code I’m using now], but it seems to me on gfortran they’re a little slow compared to the sync all statement. Perhaps that’s just my lack of experience with them.