Helpful stack traces? Not so Much

I am dabbling around with Node.js at work these days and we are trying out Jake as a build script. Jake itself is not so bad and the syntax is pretty neat, with a very small DSL for writing build scripts in JavaScript. But, with some google-fu, it’s not that hard to find accounts of people not knowing what to make of a node stack trace. So, here’s what I got when running a build script:

nikopol: $ jake --trace build-extension
jake aborted.
Error: Process exited with error.
    at fail (~/nvm/v0.8.2/lib/node_modules/jake/lib/api.js:221:18)
    at utils.mixin.exec (~/nvm/v0.8.2/lib/node_modules/jake/lib/utils/index.js:64:9)
    at EventEmitter.emit (events.js:91:17)
    at ChildProcess.utils.mixin._run (~/nvm/v0.8.2/lib/node_modules/jake/lib/utils/index.js:186:20)
    at ChildProcess.EventEmitter.emit (events.js:91:17)
    at Process._handle.onexit (child_process.js:674:10)

Hookay, something is clearly wrong here but what is it? There’s some event emitting going on, and some mixins being visited. And an exec() there too. Well, if we inspect the build script there is exec’ing of some shell commands for catting some files together. But what is the error being thrown from the shell command? Turns out, the error is actually a missing directory. Jake and Node could really be more helpful by giving some hints of that. No mention of the underlying OS error, no mention of the exit status, nor the command throwing the error (the exec call can take an array of commands to exec) or anything. Score -1 for Jake when it comes to good error messages. I’ll see if I’ll try to fork it and submit a patch on the mixin._run method to spare some other soul some useless debugging.