Comment 3 for bug 1581221

The nvme0n1 device does not have a 'by-id' entry in the device tree but it does have a by-uuid entry:

ubuntu@omaha:/dev/disk$ ll by-dname/
total 0
drwxr-xr-x 2 root root 60 May 12 21:28 ./
drwxr-xr-x 5 root root 100 May 12 21:28 ../
lrwxrwxrwx 1 root root 13 May 12 21:28 bcache0 -> ../../bcache0
ubuntu@omaha:/dev/disk$ ll by-id/
total 0
drwxr-xr-x 2 root root 200 May 12 21:28 ./
drwxr-xr-x 5 root root 100 May 12 21:28 ../
lrwxrwxrwx 1 root root 9 May 12 21:28 ata-MB1000GCEEK_WCAW37040132 -> ../../sda
lrwxrwxrwx 1 root root 10 May 12 21:28 ata-MB1000GCEEK_WCAW37040132-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 May 12 21:28 ata-MB1000GCEEK_WCAW37040132-part2 -> ../../sda2
lrwxrwxrwx 1 root root 9 May 12 21:28 ata-MB1000GCEEK_WCAW37073471 -> ../../sdb
lrwxrwxrwx 1 root root 9 May 12 21:28 wwn-0x50014ee25eda851b -> ../../sdb
lrwxrwxrwx 1 root root 9 May 12 21:28 wwn-0x50014ee25edb5d76 -> ../../sda
lrwxrwxrwx 1 root root 10 May 12 21:28 wwn-0x50014ee25edb5d76-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 May 12 21:28 wwn-0x50014ee25edb5d76-part2 -> ../../sda2
ubuntu@omaha:/dev/disk$ ll by-uuid/
total 0
drwxr-xr-x 2 root root 120 May 12 21:28 ./
drwxr-xr-x 5 root root 100 May 12 21:28 ../
lrwxrwxrwx 1 root root 10 May 12 21:28 56a8bab5-971f-45a6-9bc0-1d6c2c9daae7 -> ../../sda2
lrwxrwxrwx 1 root root 10 May 12 21:28 5f294c60-fd32-48df-86d1-41c5f133b9f2 -> ../../sda1
lrwxrwxrwx 1 root root 13 May 12 21:28 6e032f96-81f3-4a0d-aa31-ed07e747119c -> ../../nvme0n1
lrwxrwxrwx 1 root root 13 May 12 21:28 a5844495-a15d-4b66-aff7-044fb7dce11c -> ../../bcache0

See https://pastebin.canonical.com/156389/ for better formatting.