git - composer.lock is killing my push to heroku? -

i added .gitignore b.c. don't need in repo , of sudden heroku not accept push.

heroku runs checks, based on selected repo language / technology, when push code git pre-receive hooks. trying run php app. 1 of checks php repos enforces repo must include composer.json. if don't need must commit empty json:

the heroku php support applied applications when application has file named composer.json in root directory. if application has no composer dependencies, must include @ least empty ({}) composer.json in order recognized php application.

and have dependencies in it, composer.lock required:

if composer.json specifies dependencies of kind in require section, corresponding composer.lock gets generated running composer update must committed repository

and can push code github because doesn't have such hook.