There is a new GUI based on Qt framework since Wireshark version 2.0. Since the version 2.4, the legacy GTK+ GUI is disable by default. We should drop this GUI completely, as it is not supported any more. Link to upstream release notes: https://www.wireshark.org/docs/relnotes/wireshark-2.4.0.html
This bug appears to have been reported against 'rawhide' during the Fedora 28 development cycle. Changing version to '28'.
When this change was made, nothing was set to obsolete wireshark-gtk. This means upgrades fail unless --allowerasing is used. This should be fixed: retired packages *must* be properly obsoleted.
Note, also, the 'wireshark-qt' subpackage seems to have disappeared too, and similarly causes issues on upgrade as it is not obsoleted.
Thanks Adam, I am fixing this right away.
new version in rawhide wireshark-2.6.0-2.fc29 should fix this