Heads up: the Heroku Node buildpack might be breaking your builds

There seems to have been a regression in the Heroku Node buildpack. If your Node app builds with the Heroku buildpack (look at the [build] section of fly.toml) and you don’t have a Procfile, your build might fail with an error like this:

ERROR: failed to launch: determine start command: when there is no default process a command is required

You can work around this by adding a Procfile with this line:

web: npm start

More details:


Note that the Hello Node app example does not work because of this. I opened an issue for it.