docs(aio) - yarn post-install failure due to --source-map not being provided in package.json

I’m submitting a…

[ ] Regression (a behavior that used to work and stopped working in a new release)
[X] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

When performing ‘yarn’ as instructed in AIO master documentation, failure occurs with error in fs module (fs.js:641) on binding.open(pathModule._makeLong(path), stringToFlags(flags), mode);. Bubbled up error is “TypeError: path must be a string or Buffer”.

Expected behavior

‘yarn’ installs dependencies without error, including the execution of ‘postinstall’.

Minimal reproduction of the problem with instructions

Pull latest angular repo on Windows 7 machine and attempt to follow the instructions contained within aio\readme.md - beginning with simply running ‘yarn’.

What is the motivation / use case for changing the behavior?

Documentation should build using the documented build process.

Environment

Angular version: 4.3.1


For Tooling issues:
- Node version: 6.11.2  
- Platform:  Windows 7 x64

Others:


If you look at the package.json in angular/aio/ you will note that the 'postinstall' has a trailing --source-map, but that there is no output file specified for the --source-map flag for uglifyjs.  Removing the trailing --source-map allows for yarn install without error.  Providing a valid value for --source-map also results in a yarn install without error.

If you debug uglifyjs, --source-map without valid path ARGS.source_map comes through as truthy and so "if(SOURCE_MAP)" is active, though ARGS.source_map does not contain a valid path - hence the error.

[mattezell]

You da man! Thanks for the education, @gkalpak .

I’ve blown away my node_modules and everything is exactly as you described now that I’ve reran yarn 0.24.6…

Bare minimum, I am hoping that others banging their head in frustration over this error stumble here to get a quick answer (as I couldn’t find anything on this specifically last night or this morning) 😃

Thanks again for your assistance!

[gkalpak]

If you remove node_modules/ and install again using yarn 0.24.6 everything should work as expected. The issue happens because yarn 0.27.5 has installed an older version of uglifyjs in the node_modules/.bin/ directory. That old, incorrect version of uglifyjs has a different API (i.e. expects different command-line arguments) and thus breaks.