The packages for Singularity in EPEL7 are still at 2.6.0. There has been a major rewrite for 3.x, and it would be great to get the current release available in EPEL, either as an update to the existing package, or as a parallel "singularity3" package.
I have started to work on it. The version of golang in rhel7 was too old until today when the latest version was released in epel7 (because RHEL 7.6 removed golang except in devtoolset). Beyond that, since singularity-3 is such a major update, it's going to require a lot of testing before I'll be willing to let it replace singularity-2.6.0 as the default. I think there are some things that will break current users and I want to avoid that as much as possible. I expect it will take at least one more release of singularity 3.x. Meanwhile I think I'll put it in the testing repositories.
I'd rather avoid a singularity3 package. singularity-3 does attempt to be mostly compatible with singularity-2, it's just going to take a little more work before it is close enough.
singularity-3.0.3 is now the default for f28 and f29. However I still want to see more improvements and testing before putting singularity-3 in EPEL, to make sure that it doesn't break use cases of people using it in production. I know of one issue that does break a production use case, in https://github.com/sylabs/singularity/issues/2588, so I need to wait at least until that is fixed. Meanwhile I don't want to put it into epel-testing either, in case there's another security release like 2.6.1; I wouldn't want a singularity-3 version in testing to get in the way of a 2.6.2.
This is to be done in bug #1693909. singularity-3.1.1 is now in epel-testing. Please give karma.
*** This bug has been marked as a duplicate of bug 1693909 ***