I just installed todays daily build of Xenial with EFI and ran into the same problem.


$ sudo blkid
/dev/nvme0n1: PTUUID="7b6240b1-61b5-4fc7-939a-6a78708bdaad" PTTYPE="gpt"
/dev/nvme0n1p1: UUID="30E3-3A90" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="f92f5e37-7518-4e1e-91e2-f6a39b4b32c1"
/dev/nvme0n1p2: UUID="544fb035-9adf-433d-a291-47180b257560" TYPE="ext4" PARTUUID="429cab6f-729e-4055-903d-dced0f6b6529"
/dev/nvme0n1p3: UUID="f11492fb-f9bf-4699-80a9-8df106f1ed0c" TYPE="swap" PARTUUID="05a0be8e-8a2e-4e94-b74a-f3c620534f1a"


$ swapon -s
Filename				Type		Size	Used	Priority
/dev/nvme0n1p3                         	partition	33417212	0	-1


$ printf "x\np\n" | sudo fdisk /dev/nvme0n1

Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): 
Expert command (m for help): Disk /dev/nvme0n1: 477 GiB, 512110190592 bytes, 1000215216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 7B6240B1-61B5-4FC7-939A-6A78708BDAAD
First LBA: 34
Last LBA: 1000215182
Alternative LBA: 1000215215
Partition entries LBA: 2
Allocated partition entries: 128

Device             Start        End   Sectors Type-UUID                            UUID                                 Name            Attrs
/dev/nvme0n1p1      2048    1050623   1048576 C12A7328-F81F-11D2-BA4B-00A0C93EC93B F92F5E37-7518-4E1E-91E2-F6A39B4B32C1 EFI System Partition
                                                                                                                                        
/dev/nvme0n1p2   1050624  933380095 932329472 0FC63DAF-8483-4772-8E79-3D69D8477DE4 429CAB6F-729E-4055-903D-DCED0F6B6529                 
/dev/nvme0n1p3 933380096 1000214527  66834432 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F 05A0BE8E-8A2E-4E94-B74A-F3C620534F1A


$ ls -l /run/systemd/generator/
total 16
-rw-r--r-- 1 root root 374 Mar 18 16:17 boot-efi.mount
drwxr-xr-x 2 root root  60 Mar 18 16:17 cryptsetup.target.requires
drwxr-xr-x 2 root root  60 Mar 18 16:17 dev-disk-by\x2duuid-f11492fb\x2df9bf\x2d4699\x2d80a9\x2d8df106f1ed0c.device.wants
drwxr-xr-x 2 root root  60 Mar 18 16:17 dev-mapper-cryptswap1.device.d
drwxr-xr-x 2 root root  60 Mar 18 16:17 dev-mapper-cryptswap1.device.requires
-rw-r--r-- 1 root root 188 Mar 18 16:17 dev-mapper-cryptswap1.swap
drwxr-xr-x 2 root root  60 Mar 18 16:17 hwclock.service.d
drwxr-xr-x 2 root root  80 Mar 18 16:17 local-fs.target.requires
drwxr-xr-x 2 root root  60 Mar 18 16:17 local-fs.target.wants
-rw-r--r-- 1 root root 277 Mar 18 16:17 -.mount
drwxr-xr-x 2 root root  60 Mar 18 16:17 multi-user.target.wants
drwxr-xr-x 2 root root  60 Mar 18 16:17 networking.service.d
drwxr-xr-x 2 root root  60 Mar 18 16:17 remote-fs.target.d
drwxr-xr-x 2 root root  60 Mar 18 16:17 sendsigs.service.d
drwxr-xr-x 2 root root  60 Mar 18 16:17 swap.target.requires
-rw-r--r-- 1 root root 947 Mar 18 16:17 <email address hidden>
drwxr-xr-x 2 root root  60 Mar 18 16:17 umountfs.service.d
drwxr-xr-x 2 root root  60 Mar 18 16:17 umountnfs.service.d