On Sun, Nov 3, 2019 at 1:02 AM ToddAndMargo via test <test@lists.fedoraproject.org> wrote:
Hi All,

Fedora 30, attempting to upgrade to Fedora 31

# dnf system-upgrade download --refresh --releasever=31 --allowerasing
--best --skip-broken

Error:
  Problem: cannot install the best update candidate for package
qemu-system-x86-core-2:4.1.0-4.fc30.x86_64
   - problem with installed package
qemu-system-x86-core-2:4.1.0-4.fc30.x86_64
   - package qemu-system-x86-core-2:4.1.0-5.fc31.x86_64 requires
libvirglrenderer.so.0()(64bit), but none of the providers can be installed
   - package qemu-system-x86-core-2:4.1.0-2.fc31.x86_64 requires
libvirglrenderer.so.0()(64bit), but none of the providers can be installed
   - cannot install the best update candidate for package
virglrenderer-0.8.0-1.20191002git4ac3a04c.fc30.x86_64
   - cannot install both
virglrenderer-0.7.0-4.20190424gitd1758cc09.fc31.x86_64 and
virglrenderer-0.8.0-1.20191002git4ac3a04c.fc31.x86_64
   - qemu-system-x86-core-2:4.1.0-4.fc30.x86_64 does not belong to a
distupgrade repository
(try to add '--skip-broken' to skip uninstallable packages)

First, I believe you might avoid some trouble if you don't specify --best. Might not apply to this case. (You use --best exactly when you want to see dependency problems with the latest packages available).

Second, virglrenderer-0.8.0 is not available in Fedora 31, there is 0.7.0. So you use some additional repositories, probably something containing bleeding edge qemu builds. You can use "dnf repolist" to see your repositories. Either wait until the third-party repository functions properly, or disable it and use "dnf distrosync" to sync to Fedora-provided package versions.