I tested the upgrade on an Ubuntu 20.10 system on which I had bind mounted an empty directory to /sys/class/dmi (sudo mount -o ro,bind dmi /sys/class/dmi). With the version of the release upgrader in -updates I was not able to upgrade to Ubuntu 21.04. Testing the version of the release upgrader in -proposed I was able to upgrade to Ubuntu 21.04.
ubuntu@assured-caribou:/tmp/ubuntu-release-upgrader-cqvcwbjy$ cat DistUpgradeVersion.py
VERSION = '21.04.13'
ubuntu@assured-caribou:/tmp/ubuntu-release-upgrader-cqvcwbjy$ ls -lh /sys/class/dmi/
total 0
I tested the upgrade on an Ubuntu 20.10 system on which I had bind mounted an empty directory to /sys/class/dmi (sudo mount -o ro,bind dmi /sys/class/dmi). With the version of the release upgrader in -updates I was not able to upgrade to Ubuntu 21.04. Testing the version of the release upgrader in -proposed I was able to upgrade to Ubuntu 21.04.
ubuntu@ assured- caribou: /tmp/ubuntu- release- upgrader- cqvcwbjy$ cat DistUpgradeVers ion.py assured- caribou: /tmp/ubuntu- release- upgrader- cqvcwbjy$ ls -lh /sys/class/dmi/
VERSION = '21.04.13'
ubuntu@
total 0