In mantic, we migrated livecd-rootfs to use losetup -P instead of kpartx, with the expectation that this would give us a reliable, race-free way of loop-mounting partitions from a disk image during image build.
In noble, we are finding that it is no longer reliable, and in fact fails rather often.
It is most noticeable with riscv64 builds, which is the architecture where we most frequently ran into problems before with kpartx. The first riscv64+generic build in noble where the expected loop partition device is not available is
The failure is however not unique to riscv64, and the autopkgtest for the latest version of livecd-rootfs (24.04.7) - an update that specifically tries to add more debugging code for this scenario - has also failed on ppc64el.
In mantic, we migrated livecd-rootfs to use losetup -P instead of kpartx, with the expectation that this would give us a reliable, race-free way of loop-mounting partitions from a disk image during image build.
In noble, we are finding that it is no longer reliable, and in fact fails rather often.
It is most noticeable with riscv64 builds, which is the architecture where we most frequently ran into problems before with kpartx. The first riscv64+generic build in noble where the expected loop partition device is not available is
https:/ /launchpad. net/~ubuntu- cdimage/ +livefs/ ubuntu/ noble/cpc/ +build/ 531790
The failure is however not unique to riscv64, and the autopkgtest for the latest version of livecd-rootfs (24.04.7) - an update that specifically tries to add more debugging code for this scenario - has also failed on ppc64el.
https:/ /autopkgtest. ubuntu. com/packages/ l/livecd- rootfs/ noble/ppc64el
The first failure happened on November 16. While there has been an update to the util-linux package in noble, this did not land until November 23.