I'm unable to upgrade 15.04 to 16.04 LTS. Support has ended and all codes to edit sources.list have failed to work. I cannot use gksu since I don't have it and I'm unable to install it from software center or terminal. sed
commands have also not worked. Software&updates is just repeating Failed to download repository
even after making changes given here:
How to install software or upgrade from an old unsupported release?
Output of trying to install gksu
:
gksudo gedit /etc/apt/sources.list
The program 'gksudo' is currently not installed. You can install it by typing:
sudo apt-get install gksu
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package gksu is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source
E: Package 'gksu' has no installation candidate`
Output of sed
command:
sudo sed -i.bak 's_ftp.iitb.ac.in/distributions/ubuntu/archives_http://old-releases.ubuntu.com_g' /etc/apt/sources.list
sed: -e expression #1, char 80: unknown option to `s'
and without 'g'
sudo sed -i.bak
's_ftp.iitb.ac.in/distributions/ubuntu/archives_http://old-releases.ubuntu.com_' /etc/apt/sources.list
sed: -e expression #1, char 79: unknown option to s'