$sudo apt install firefox
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  fonts-stix | otf-stix
The following NEW packages will be installed:
  firefox
0 upgraded, 1 newly installed, 0 to remove and 162 not upgraded.
Need to get 0 B/41.1 MB of archives.
After this operation, 165 MB of additional disk space will be used.
Selecting previously unselected package firefox.
(Reading database ... 463889 files and directories currently installed.)
Preparing to unpack .../firefox_61.0.1-1_amd64.deb ...
Unpacking firefox (61.0.1-1) ...
Replaced by files in installed package parrot-interface-common (4.2+parrot2) ...
Processing triggers for mime-support (3.61) ...
Processing triggers for desktop-file-utils (0.23-3) ...
Processing triggers for bamfdaemon (0.5.3-3) ...
Rebuilding /usr/share/applications/bamf-2.index...
Setting up firefox (61.0.1-1) ...
update-alternatives: error: alternative path /usr/bin/firefox doesn't exist
dpkg: error processing package firefox (--configure):
 installed firefox package post-installation script subprocess returned error exit status 2
Processing triggers for man-db (2.8.4-2) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Errors were encountered while processing:
 firefox
Configuring sandbox profiles....
Sandbox profiles updated!
E: Sub-process /usr/bin/dpkg returned an error code (1)