Cannot run `npm install` on a newly-cloned repository

[schmod]

Running npm install on a freshly-cloned repository fails, and leaves no node_modules folder intact:

> angularjs@ preinstall /home/schmod/source/angular.js
> node scripts/npm/check-node-modules.js --purge

:-( npm dependencies are stale or in an unknown state!
    Purging 'node_modules'...

> angularjs@ postinstall /home/schmod/source/angular.js
> node scripts/npm/copy-npm-shrinkwrap.js

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Failed to copy `npm-shrinkwrap.json` to `node_modules/npm-shrinkwrap.cached.json`:
{ [Error: ENOENT: no such file or directory, open 'node_modules/npm-shrinkwrap.cached.json']
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: 'node_modules/npm-shrinkwrap.cached.json' }
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

NPM v3.3.8; Node 4.2.1; Ubuntu 15.04

[schmod]

It looks like the changes introduced in #12792 / d3de006 will delete the user's node_modules folder when the preinstall script runs if a NPM Shrinkwrap cache file is not present.

I'm assuming that NPM v3.x doesn't add this file before the preinstall scripts are run, which is causing the preinstall script to wipe the node_modules folder that npm install just created.

I'm not sure what the original intent was here, so I can't recommend a fix.

[gkalpak]

I don't see how the changes on #12792 could cause this issue.
The node_modules/ directory is purged before npm install, then npm install runs and creates the node_modules/ directory (installing all necessary modules) and finally the (already existing) npm-shrinkwrap.json file is copied over to node_modules/npm-shrinkwrap.cached.json (which is created then; it doesn't exist already).

The only thing that would make sense, would be if somehow the underlying file created with var ws = fs.createWriteStream(dstPath); (where dstPath is node_modules/npm-shrinkwrap.cached.json) isn't created in time for getting written to (with rs.pipe(ws);.
But this shouldn't be the case, since this is supposed to be taken care of (for quire some time now) in Node.js' fs module.

I am clueless here :( @schmod, can you reproduce it consistently ?

_{I have only tried on npm v2.x, but I would be surprized if it tuned out to be npm-specific.}

[schmod]

I just did a fresh clone of the repo on another computer with NPM 3.3.9, and duplicated the issue.

It appears that this is NPM-specific, as NPM's docs only seem to promise that a package's preinstall script will be executed before that same package's install script. It specifically does not promise that the script will run before npm downloads and installs the package's dependencies.

This may be the same issue as npm/npm#9916, although I suspect that very few packages are depending on the NPM lifecycle functioning this way.

tl;dr; Angular's preinstall script appears to depend on an undocumented behavior in NPM that has changed in version 3.x.

[gkalpak]

I confirm that it doesn't work with npm v3.3.9. It seems that the preinstall scripts are run after the dependencies have been installed. I suggest we wait and see what is the response to npm/npm#9916.

@IgorMinar, any insight on this ? This should also affect ng2 (but I haven't tried it).

[schmod]

It looks like Node 5.0.0 will be shipping soon, and will be bundled with NPM 3.6.6.

nodejs/node#3466