When I saw that 19.04 was available, I started the upgrade process. After I'd started it, I remembered I had a presentation in the morning and thought I'd better wait until after it was over. I hit cancel and didn't worry about it.
After that, I came back into it and it's telling me that it can only do a partial upgrade. One of the reasons for this seems to be that I canceled the update.
I tried running /usr/lib/ubuntu-release-upgrader/check-new-release-gtk
but it keeps telling me I need to run all updates for my installation before I do the upgrade. I don't seem to be able to get past it. I think it's finding the upgrade to 19.04 because I can't keep going.
Is there a way to reset the upgrade process to allow me get the installation started again?