babel-node not working when launching with ecosystem.config.js

What's going wrong?

babel-node doesn't transpile properly when launching app with a config.js file. Using CLI arguments works, ex: pm2 start --interpreter babel-node app.js.

When launching from the config.js file, what's weird is that when I run pm2 info app it says that the interpreter is babel-node, however I still get errors on my ES6 syntax. When launching with CLI arguments, it appears everything is transpiling correctly and no errors are logged.

How could we reproduce this issue?

The config file I use is:

  apps : [{
    name: 'app',
    script: 'app.js',
    watch: '.',
    interpreter: '/usr/bin/babel-node',
    exec_mode: 'fork'
  }]
};

The CLI command that works as expected is pm2 start --interpreter babel-node app.js

Supporting information

$ pm2 report

Reproduce the discrepancy using the supplied ecosystem.config.js and compare it with pm2 start --interpreter babel-node app.js. Start by tracing how the config-file interpreter value is handled versus the CLI value, then verify that an ES6 app launches without syntax errors in both cases.