usando el composer uci para instalar symfony 2.7 me da el siguiente error
[RuntimeException]
Failed to clone https://github.com/doctrine/lexer.git via https, ssh, git protocols, aborting.

– https://github.com/doctrine/lexer.git
Cloning into ‘E:instaladosxampphtdocsSymvendordoctrinelexer’…
fatal: unable to access ‘https://github.com/doctrine/lexer.git/’: Couldn’t resolve host ‘github.com’

– git@github.com:doctrine/lexer.git
Cloning into ‘E:instaladosxampphtdocsSymvendordoctrinelexer’…
ssh: Could not resolve hostname github.com: Temporary failure in name resolution
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

– git://github.com/doctrine/lexer.git
Cloning into ‘E:instaladosxampphtdocsSymvendordoctrinelexer’…
fatal: Unable to look up github.com (port 9418) (╔ste es normalmente un error temporal durante la resoluci¾n de nombres de host y significa que el servidor local n
o recibi¾ una respuesta de un servidor autoritativo. )
alguien puede ayudarme a resolver