why is composer reading dependencies of branches

Sun, Mar 31, 2019

$ composer update
Loading composer repositories with package information
Reading composer.json of drutopia/drutopia (124-a-visitor-sees-the-active-menu-t
Reading composer.json of drutopia/drutopia (69-install-signup)
Updating dependencies (including require-dev)
Package operations: 0 installs, 1 update, 0 removals

It’s those first two lines after composer update that confuse me. Why is it checking out what random old branches have to say about what it should load? Doesn’t it already know the branch it should be getting for drutopia/drutopia? It doesn’t seem complicated.

It seems using a no-api option will prevent this, per https://www.reddit.com/r/PHP/comments/5lwy6w/improve_speed_of_composer_update_by_not_using_the/dc02ntt/