Comment 37 for bug 1690980

The apport issue seems to be due to a bug in xenial's shared-mime-info:

root@xenial-test:/home/rbalint# time apt-get install -y --allow-downgrades --reinstall apport=2.20.1-0ubuntu2
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libllvm3.8 libmircommon5 linux-image-4.4.0-78-generic
  linux-image-4.4.0-83-generic
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 20 not upgraded.
Need to get 0 B/119 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 271938 files and directories currently installed.)
Preparing to unpack .../apport_2.20.1-0ubuntu2_all.deb ...
Unpacking apport (2.20.1-0ubuntu2) over (2.20.1-0ubuntu2) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu18) ...
Processing triggers for shared-mime-info (1.5-2ubuntu0.1) ...
Processing triggers for hicolor-icon-theme (0.15-0ubuntu1) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up apport (2.20.1-0ubuntu2) ...

real 1m36.802s
user 0m1.812s
sys 0m0.796s

root@xenial-test:/home/rbalint# time update-mime-database.real /usr/share/mime

real 1m53.622s
user 0m0.264s
sys 0m0.096s

This takes ~2s on zesty:
root@zesty-test:/home/rbalint# time update-mime-database.real /usr/share/mime
Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'

real 0m2.146s
user 0m0.272s
sys 0m0.104s

This may worth further investigation and possibly an SRU.