SPFX Package Build Failure

I am struggling to rebuild a package. It built and deployed fine the first time around. It is a simple Framework Extension to inject a stylesheet. I misspelled something in the URL updated it and went through the process.
gulp clean
gulp bundle --ship
gulp build --ship
All is good everything passes.
gulp package-solution --ship
Task Warnings: 1.
Build Failed because task wrote output to stderr.
The only warning is "Admins can make this solution available to all sites immediately, but the solution also contains a feature element for provisioning. Feature.xml elements are not automatically applied unless the solution is explicitly installed on a site."
I've tried to run just gulp package-solution as this is just a development bulid but the URL fails to update and that will be a short term solution anyway.
Any ideas on how to get over this? I'm stumped especially since gulp build --ship works.