I installed the version of apport from xenial-proposed and can confirm that choices greater than 9 now work.
*** Please select the cloud vendor or environment in which this instance is running
Choices: 1: Amazon - Ec2 2: AliYun 3: AltCloud 4: Azure 5: Bigstep 6: CloudSigma 7: CloudStack 8: DigitalOcean 9: GCE - Google Compute Engine 10: MAAS 11: NoCloud 12: OpenNebula 13: OpenStack 14: OVF 15: Scaleway 16: SmartOS 17: VMware 18: Other C: Cancel Please choose (1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/C): 18
I installed the version of apport from xenial-proposed and can confirm that choices greater than 9 now work.
*** Please select the cloud vendor or environment in which this instance is running
Choices: 4/5/6/7/ 8/9/10/ 11/12/13/ 14/15/16/ 17/18/C) : 18
1: Amazon - Ec2
2: AliYun
3: AltCloud
4: Azure
5: Bigstep
6: CloudSigma
7: CloudStack
8: DigitalOcean
9: GCE - Google Compute Engine
10: MAAS
11: NoCloud
12: OpenNebula
13: OpenStack
14: OVF
15: Scaleway
16: SmartOS
17: VMware
18: Other
C: Cancel
Please choose (1/2/3/