Reviewing your build log, I see a few possible issues:
- You are trying to build a release app but you are using a development provisioning profile based on this error in your log:
error: exportArchive Provisioning profile "XXXXXX" is not an "iOS App Store" profile. - It appears that you may have a plugin that’s not been updated for cordova-ios engine 8 - or you have that plugin version locked and haven’t allowed the updates to occur. I would either use engine 7.1.1 or check your plugins for updates.