Como corrigir o erro “não foi possível conectar ao host” ao instalar o Unity Webapps?

Question

Eu recebo os seguintes erros quando tento instalar o Unity Webapp no Ubuntu 12.04 :

root@detro-X101H:/home/detro# sudo add-apt-repository ppa:webapps/preview
Traceback (most recent call last):
  File "/usr/bin/add-apt-repository", line 125, in <module>
    ppa_info = get_ppa_info_from_lp(user, ppa_name)
  File "/usr/lib/python2.7/dist-packages/softwareproperties/ppa.py", line 80, in get_ppa_info_from_lp
    curl.perform()
pycurl.error: (7, "couldn't connect to host")

Minha conexão com a Internet parece estar funcionando bem. Eu acho que sou usando um servidor proxy. Quando executo apt-get update como root, recebo essas mensagens de erro ( saída completa aqui ):

W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F1773AF13B1510FD
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8CD60EC948894010
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6A45934EA9D4C08B
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C2518248EEA14886
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 32B18A1260D8DA0B
W: GPG error: https://private-ppa.launchpad.net precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E131728675254D99
W: Failed to fetch http://ppa.launchpad.net/launchpad.net/~scopes-packagers/ubuntu/dists/precise/main/source/Sources  404  Not Found

E: Some index files failed to download. They have been ignored, or old ones used instead.

Aqui está a saída de cat /etc/apt/sources.list; for X in /etc/apt/sources.list.d/*; do echo; echo; echo "** $X:"; echo; cat $X; done (que lista todas as fontes de software ativadas).

Sou novo para o Linux e fornecerei mais detalhes conforme necessário.

    

Answer 1

O melhor convidado é que você foi afetado por uma interrupção no serviço LaunchPad ou por um problema com sua rede:

$ sudo add-apt-repository ppa:webapps/preview
You are about to add the following PPA to your system:
 This is the preview for Unity WebApps for Ubuntu Quantal (12.10) Precise (12.04).

To install...

sudo add-apt-repository ppa:webapps/preview
sudo apt-get update
sudo apt-get install unity-webapps-preview
Restart your session (logout and back in)

To uninstall...

sudo apt-get install ppa-purge
sudo ppa-purge ppa:webapps/preview
 More info: https://launchpad.net/~webapps/+archive/preview
Press [ENTER] to continue or ctrl-c to cancel adding it

Como você pode ver, posso adicionar o repositório. A única pista é:

curl.perform()
pycurl.error: (7, "couldn't connect to host")

Isso significa que a biblioteca de curls do python não pôde acessar os servidores do LP.