I apologize that this notice is late. Three weeks ago, there was an update to the apptainer package (formerly called singularity) in EPEL that may have caused functionality for users to break, especially on EPEL7. Apptainer is a container system that is popular especially for High Performance Computing applications.
This was the first release in EPEL under the new name. Because of the name change, the configuration directory name changed, and previous system-wide custom configuration is not automatically carried forward. Warnings are printed if the old configuration directory still exists (which happens when singularity configuration had been customized). The command is still available under the old name singularity, so that part is still compatible.
More significantly, the apptainer-1.1 release changed the default package to be "rootless" by not including a setuid-root component. As a result, if unprivileged user namespaces are not enabled, most operations will fail. System administrators in that case have to either enable unprivileged user namespaces or separately install an apptainer-suid package. This is particularly an issue on EL7 because there user namespaces are not enabled by default. The reason the default was changed is that the new version now supports doing most common operations without setuid, using unprivileged FUSE mounts, and the maintainers believe that unprivileged user namespaces are inherently more secure than setuid-root.
For more details please see: https://apptainer.org/docs/user/1.1/security.html#setuid-user-namespaces https://apptainer.org/docs/admin/1.1/user_namespace.html#rhel-centos-7 https://apptainer.org/docs/admin/1.1/installation.html https://apptainer.org/docs/admin/1.1/singularity_migration.html https://github.com/apptainer/apptainer/releases
If you find any problems please report them to https://github.com/apptainer/apptainer/issues
Dave