Não é possível instalar o curl no Ubuntu 16.04

Question

Eu só quero instalar vestacp no meu Ubuntu 16.04 usando curl , por isso precisa de mim para instalar curl por

apt-get install curl

mas isso me dá esse erro:

root@cindyadonia:/# apt-get install curl
Reading package lists... Done
Building dependency tree       
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

Eu segui este tópico, mas ainda não funciona. O programa 'curl' é atualmente não instalado

O que eu senti falta? Por favor me avise.

Aqui está o meu sources.list . Eu adicionei alguns # que eu realmente não entendo. Por favor, corrija-me.

# deb cdrom:[Ubuntu-Server 16.04.4 LTS _Xenial Xerus_ - Release amd64 (20180228)]/ xenial main r$

# deb cdrom:[Ubuntu-Server 16.04.4 LTS _Xenial Xerus_ - Release amd64 (20180228)]/ xenial main r$

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

## Major bug fix updates produced after the final release of the
## distribution.
# deb http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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://archive.ubuntu.com/ubuntu/ xenial universe
# deb-src http://archive.ubuntu.com/ubuntu/ xenial universe
# deb http://archive.ubuntu.com/ubuntu/ xenial-updates universe
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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://archive.ubuntu.com/ubuntu/ xenial multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ xenial multiverse
# deb http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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 xenial partner
# deb-src http://archive.canonical.com/ubuntu xenial partner

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


# deb http://archive.ubuntu.com/ubuntu xenial main universe multiverse restricted
# deb http://archive.ubuntu.com/ubuntu trusty universe

    

Answer 1

Substitua seu arquivo sources.list por isso. Eu descomentei todos os repositórios recomendados (main / restricted / universe / multiverse de xenial, xenial-updates e xenial-security; sem backports, sem parceiro e sem fontes) e removi algumas linhas desnecessárias:

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

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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://archive.ubuntu.com/ubuntu/ xenial universe
# deb-src http://archive.ubuntu.com/ubuntu/ xenial universe
deb http://archive.ubuntu.com/ubuntu/ xenial-updates universe
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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://archive.ubuntu.com/ubuntu/ xenial multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ xenial-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 xenial partner
# deb-src http://archive.canonical.com/ubuntu xenial partner

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

Depois disso, baixe as listas de pacotes usando:

sudo apt update

Agora, como você desativou as atualizações de pacote por um tempo, primeiro atualize seu sistema:

sudo apt upgrade

Depois disso, instale curl como você pretendia originalmente:

sudo apt install curl