Comment 9 for bug 1838245

the case I tested:
install the dkms which already patched (also can be found in my ppa[1])
1. install a dkms which for a kernel module system already installed.
e.g. ath10k of my testing ppa : [1]
1.1. the dkms can be installed well.

2. install a dkms which has OBSOLETE_BY and FORCE
e.g.ath10k of my testing ppa : [1] (source code in [2])
 + the target dkms defined OBSOLETE_BY and FORCE
   - OBSOLETE_BY="4.15.0-1033": https://git.launchpad.net/~alextu/+git/oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms/tree/oem-wifi-qualcomm-ath10k-lp1803647-4.15/dkms.conf?h=lp1838245#n8
   - https://git.launchpad.net/~alextu/+git/oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms/tree/oem-wifi-qualcomm-ath10k-lp1803647-4.15.force?h=lp1838245
 + user install dkms on a system which installed kernel version less than OBSOLETE_BY and another kernel higher than OBSOLETE_BY
  - in my system there're 2 kernels 4.15.0-1030 and 4.15.0-1045
 + the dkms can be installed well with kernel 4.15.0-1030, and not be installed with 4.15.0-1045

also attached the log came from patched dkms script during install dkms [2]

[1]:https://code.launchpad.net/~alextu/+archive/ubuntu/dkms-2.3-lp1838245
[2]:https://code.launchpad.net/~alextu/+git/oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms/+ref/lp1838245