Por que o pacote octave não está aparecendo na pesquisa do apt?

Question

Estou usando o 'termux' (emulador de terminal do Android). Eu recentemente instalei o Ubuntu dentro dele em um ambiente 'proot'. Quando eu procurei pelo pacote octave usando 'apt search octave', não consigo encontrar nenhum resultado. Então eu procurei manualmente por octave nos pacotes do Ubuntu para verificar se ele está disponível para 'armhf'. Para minha surpresa, está disponível para 'armhf'. Eu estou realmente morrendo de vontade de usar oitava no meu android. Por que ele não está aparecendo na pesquisa do apt? O que posso fazer para corrigir isso?

PesquisadepacotesdoUbuntu: link

Saída de "cat /etc/apt/sources.list"

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ artful main restricted
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ artful-updates main restricted
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://ports.ubuntu.com/ubuntu-ports/ artful universe
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful universe
deb http://ports.ubuntu.com/ubuntu-ports/ artful-updates universe
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://ports.ubuntu.com/ubuntu-ports/ artful multiverse
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful multiverse
deb http://ports.ubuntu.com/ubuntu-ports/ artful-updates multiverse
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://ports.ubuntu.com/ubuntu-ports/ artful-backports main restricted universe multiverse
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu artful partner
# deb-src http://archive.canonical.com/ubuntu artful partner

deb http://ports.ubuntu.com/ubuntu-ports/ artful-security main restricted
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-security main restricted
deb http://ports.ubuntu.com/ubuntu-ports/ artful-security universe
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-security universe
deb http://ports.ubuntu.com/ubuntu-ports/ artful-security multiverse
# deb-src http://ports.ubuntu.com/ubuntu-ports/ artful-security multiverse

    

Answer 1

O pacote octave está disponível no repositório universe :

sudo add-apt-repository universe
sudo apt update
sudo apt install octave

Página de download para a oitava :

You should be able to use any of the listed mirrors by adding a line to your /etc/apt/sources.list like this:

deb http:// artful main universe

Para o seu caso, faça o seguinte: Altere a 3ª linha para:

deb http://ports.ubuntu.com/ubuntu-ports/ artful main universe restricted

atualize seu sistema.