prabha@prabha-OptiPlex-9020:~$ su
Password:
su: Authentication failure
prabha@prabha-OptiPlex-9020:~$ sudo apt-get install -f
[sudo] password for prabha:
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 918 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up install-info (6.1.0.dfsg.1-5) ...
/usr/sbin/update-info-dir: 5: /etc/environment: EXPORT: not found
dpkg: error processing package install-info (--configure):
 subprocess installed post-installation script returned error exit status 127
Errors were encountered while processing:
 install-info
E: Sub-process /usr/bin/dpkg returned an error code (1)
prabha@prabha-OptiPlex-9020:~$ cat /etc/default/locale
#  File generated by update-locale
LANG="en_US.UTF-8"
prabha@prabha-OptiPlex-9020:~$