Drupal - Composer installing dev modules getting Authentication required (git.drupalcode.org)

This issue happens when you are requesting packages through composer from corporate network. Corporate firewall blocks the network request. The credentials it is asking is actually for corporate proxy.

Just connect to open internet and try again your issue will be probably resolved.

I figured it out! turns out my anti-virus is blocking git.drupalcode.org/. Had to add git.drupalcode.org/* to my whitelist.