The issue may have to do with the installed version of libsolv not supporting bzip2 compression. Like me, you may not have the most recent version being installed because setting priorities in the repo config files.
Failed to open: /var/cache/dnf/x86_64/7/x86_64/7/epel/...xml.bz2
See bug report 1258416.
libsolv-0.6.14-1.el7 has been pushed to the Fedora EPEL 7 stable repository. If
problems still persist, please make note of it in this bug report.
The libsolv installed from the CentOS
base repository is 0.6.11-1.el7, but the one in
epel is 0.6.14-1.el7.
yum --showduplicates --disablerepo=base list libsolv
libsolv.x86_64 0.6.11-1.el7 @base
libsolv.x86_64 0.6.14-1.el7 epel
Install libsolv from the
yum --disablerepo=base install libsolv-0.6.14-1.el7
As seen in the comments, this is still an active bug with the package repositories. This is because of
libsolv being marked as "retired" in the EPEL without an explanation (Theodor van Nahl). Dennis M. Pöpperl points out that RPMs of versions that had seemed to have been working in CentOS and RHEL are available here in the Fedora build system.