If your system is not Leap 15.0, then change repository accordingly to your needs.
Steps:
- Add repository: https://download.opensuse.org/repositories/X11:/XOrg/openSUSE_Leap_15.0/x86_64/
- Make “Full repository Vendor change”: https://en.opensuse.org/SDB:Vendor_change_update
- Update your system
- Reboot
When I tried to update only Mesa packets without other components my system had hanged.
Hi
These seems like a help question… will move to install/boot/login sub forum. Thread temporarily closed.
Hi
Thread moved and reopened 
So your repository link is incorrect, it should be one level up to included the repository data and noarch directory;
https://download.opensuse.org/repositories/X11:/XOrg/openSUSE_Leap_15.0/
Then try your switch/update.
Yes, repository link was incorrect.
I am using updated Mesa 3D and other stuff during some months.