Why is PHP Composer so slow?

Question

Why is PHP Composer so slow when all I do is init a project with zero dependencies? Here are the commands I run:

composer init

Answer 1

I was running into this issue, and it was throwing me for a curve since I don't have Xdebug installed anywhere on my machine. It turns out that it was IPv6 addressing mode failures. So to test I ran

curl --ipv4 'https://packagist.org/packages.json'
curl --ipv6 'https://packagist.org/packages.json'

IPv4 went through, but IPv6 failed. In the end, you should look to find out why you're networking stack doesn't support it, but in my case, I decided to just give preference to IPv4 traffic until I can resolve that. On CentOS I created/modified the file /etc/gai.conf and put in the following:

label       ::1/128        0
label       ::/0           1
label       2002::/16      2
label       ::/96          3
label       ::ffff:0:0/96  4
precedence  ::1/128        50
precedence  ::/0           40
precedence  2002::/16      30
precedence  ::/96          20
precedence  ::ffff:0:0/96  100

On Ubuntu you can also edit that file and uncomment the line

precedence ::ffff:0:0/96  100

Source on Rackspace Community Hub