While running apt install curl command this error has been displayed and apt-get update also not updating every packages i am not aware of this error
ubuntu@master:~$ sudo apt install curl
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package curl 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 'curl' has no installation candidate
ubuntu@master:~$ sudo apt-get update
Reading package lists... Done
sudo apt update
and check all lines are present, none missing, and no warnings or error messages. – guiverc Nov 14 '23 at 02:19