You are correct that seuss and lundmark should be identical. I rebuilt the 4.13.0-35.39 kernel in xenial to see if the issue follows the toolchain (see table below), but I failed noticed the slight differene in versions. Here's the current testing summary - next I'll rebuild 4.13.0-33.36~16.04.1 with the 5.4.0-6ubuntu1~16.04.*9* toolchain as you suggested.
4.13.0-33.36~16.04.1 | 5.4.0-6ubuntu1~16.04.8 | Fails 4.13.0-33.36 | 7.2.0-8ubuntu3.1 | OK 4.13.0-35.39 | 7.2.0-8ubuntu3.2 | OK 4.13.0-35.39 | 5.4.0-6ubuntu1~16.04.9 | OK -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1749040 Title: fails to boot on Cavium ThunderX CRB Status in linux package in Ubuntu: Confirmed Bug description: While regression testing the current linux-hwe proposed kernel (4.13.0-33.36~16.04.1), I found that it fails to boot on a Cavium ThunderX CRB. I've rebooted twice since upgrading from the current -updates kernel, and it's failed to boot both times, with different failure modes. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1749040/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : firstname.lastname@example.org Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp