! [remote rejected] master -> master (pre-receive hook declined)

After running 'git push heroku master' i get this output

and the following error:

! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/(app name).git'

[MP3Martin]

rip same

[emilienbidet]

Same issue, solved by just adding a requirements.txt file :
touch requirements.txt
git add requirements.txt
git commit -m "Fix python buildpack bug"
git push heroku master

[ZTzTopia]

Same issue, solved by just adding a requirements.txt file :
touch requirements.txt
git add requirements.txt
git commit -m "Fix python buildpack bug"
git push heroku master

thanks