"timed out waiting for NPM for package" error

I'm always getting a timed out error:

checking NPM registry
timed out waiting for NPM for package browserify
ERROR testing next working updates

The full log is here:

$  next-update
found npm path npm
next-update@0.9.2 - Tests if module's dependencies can be updated to the newer version without breaking the tests
checking if the current state works
  npm test
> js2coffee@2.1.0 test /Users/rsc/Projects/js2coffee
> mocha


  [▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬]

  303 passing (2s)
  44 pending

> tests are passing at the start
module's current dependencies:
------------------------------
module         version  type
-------------  -------  ----
escodegen      1.6.0    prod
esprima        2.5.0    prod
estraverse     1.9.1    prod
minimist       1.1.0    prod
read-input     0.2.0    prod
source-map     0.1.38   prod
browserify     5.10.1   dev
chai           1.9.1    dev
coffee-script  1.8.0    dev
coffeeify      1.0.0    dev
coffeelint     1.6.0    dev
glob           4.0.5    dev
js-yaml        3.2.1    dev
mocha          2.1.0    dev
mocha-clean    0.4.0    dev
uglify-js      2.4.16   dev
underscore     1.7.0    dev

checking NPM registry
timed out waiting for NPM for package browserify
ERROR testing next working updates

You can try it out in https://github.com/js2coffee/js2coffee (master).

Start by reproducing next-update against the js2coffee dependency set shown in the log, using the browserify registry lookup as the first investigation point. Read the timeout and registry-check path exposed by the command output, then run the project's npm test command. Done means the dependency check handles the browserify lookup without the reported timeout error.