I am unable to install erlang/Elixir on my ubuntu 18.10 cosmic system

Question

I am following the steps on for unix like systems https://elixir-lang.org/install.html#unix-and-unix-like

this is the error that I am getting

sudo apt-get install esl-erlang
Reading package lists... Done
Building dependency tree      
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 esl-erlang : Depends: libncurses5 but it is not installable
              Depends: libsctp1 but it is not installable
              Recommends: erlang-mode but it is not going to be installed
E: Unable to correct problems, you have held broken packages

I tried using asdf-vm as well but still the same libcurses5 issue is there

asdf install erlang 21.1
asdf_21.1 is not a kerl-managed Erlang/OTP installation
No build named asdf_21.1
Downloading OTP-21.1.tar.gz to /home/superuser/.asdf/plugins/erlang/kerl-home/archives
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   120  100   120    0     0    241      0 --:--:-- --:--:-- --:--:--   241
100 51.3M    0 51.3M    0     0  4747k      0 --:--:--  0:00:11 --:--:-- 3990k
Extracting source code
Building Erlang/OTP 21.1 (asdf_21.1), please wait...
WARNING: It appears that a required development package 'libncurses5-dev' is not installed.
Configure failed.
checking whether lock counters should be enabled... no
checking whether dlopen() needs to be called before first call to dlerror()... no
checking for kstat_open in -lkstat... (cached) no
checking for tgetent in -ltinfo... no
checking for tgetent in -lncurses... no
checking for tgetent in -lcurses... no
checking for tgetent in -ltermcap... no
checking for tgetent in -ltermlib... no
configure: error: No curses library functions found

Answer 1

The problem was that with cosmic the repositories were not available on http://archive.ubuntu.com .

changing them in /etc/apt/sources.list ie replacing all occurences of http://archive.ubuntu.com with http://old-releases.ubuntu.com did the trick.