pulp build --to output.js randomly stopped building output

[purescript-contrib]

pulp build --to output.js randomly stopped building output

[codygman]

I had some packages missing somehow. I found this out by running:

npm -g ls

My fix was to reinstall the only globally installed packages I had:

npm install -g grunt
npm install -g pulp

it showed me a bunch of packages were missing. I'd post the exact error but I didn't have much scrollback in that shell.

[codygman]

And it's not working again...

[codygman]

Irony keeps you going... and there is no greater irony than not being able to use Purescript because of a type error 😃

I found this out by making the child process spawned in exec.js write to stdout:

cody@cody-G46VW:/tmp/hello-sailor$ diff node_modules/pulp/exec.js ~/.nvm/versions/node/v0.12.5/lib/node_modules/pulp/exec.js 
9c9
<     stdio: [process.stdin, process.stdout, process.stderr],
---
>     stdio: [process.stdin, quiet ? "pipe" : process.stdout, process.stderr],

/tmp/hello-sailor/node_modules/pulp/exec.js:36
    c.stdout.pipe(require("concat-stream")(function(data) {
            ^
TypeError: Cannot read property 'pipe' of null
    at exec (/tmp/hello-sailor/node_modules/pulp/exec.js:36:13)
    at /tmp/hello-sailor/node_modules/pulp/exec.js:47:7
    at it (/tmp/hello-sailor/node_modules/pulp/files.js:21:7)
    at /tmp/hello-sailor/node_modules/pulp/files.js:27:11
    at f (/tmp/hello-sailor/node_modules/pulp/node_modules/glob/node_modules/once/once.js:17:25)
    at Glob.<anonymous> (/tmp/hello-sailor/node_modules/pulp/node_modules/glob/glob.js:132:7)
    at Glob.emit (events.js:107:17)
    at Glob._finish (/tmp/hello-sailor/node_modules/pulp/node_modules/glob/glob.js:171:8)
    at done (/tmp/hello-sailor/node_modules/pulp/node_modules/glob/glob.js:158:12)
    at Glob._processReaddir2 (/tmp/hello-sailor/node_modules/pulp/node_modules/glob/glob.js:353:12)

[codygman]

Okay, figuring this out now.

pulp build -t main.js

Running the above, the following is the value of r in the context of the function on line 28 of exec.js:

Reading ./output/Prelude.Unsafe/externs.purs
Reading ./output/Data.Function/externs.purs
Reading ./output/Control.Monad.Eff/externs.purs
Reading ./output/Control.Monad.Eff.Unsafe/externs.purs
Reading ./output/Control.Monad.ST/externs.purs
Reading ./output/Debug.Trace/externs.purs
Reading ./output/Main/externs.purs

If I add the seemingly unrelated -O (dead code elimination) I get a file as I should. The value of r is the file itself.

So the bug here is that a file is only written if the seemingly unrelated -O flag is specified.

[bodil]

Yes, sorry, I noticed the same thing yesterday. Essentially, pulp calls psc-make to build normally, which generates output, and psc if you specify -O. --to is specifically an argument for psc. I think I'd rather have --to be the determinant and -O the extra argument, so that if you specify --to it calls psc regardless, and if you specify -O without --to it terminates with an error.