"bin" symlink missing on some case.

[garbin]

Do you want to request a feature or report a bug?

bug
What is the current behavior?

the dependencies tree below

• PROJECT_ROOT
  • koapi
    • knex (that have a bin symlink 'knex')
    • ava (that have a bin symlink 'ava')

with npm, the 'bin' symlink knex and ava will be found at PROJECT_ROOT/node_modules/.bin

• PROJECT_ROOT
  ./node_modules/.bin/knex
  ./node_modules/.bin/ava

but yarn, there are missing. they only can be found in the package that direct dependent them.
{PROJECT_ROOT}/node_modules/koapi/node_modules/.bin

• koapp
  - koapi
  ./node_modules/.bin/knex
  ./node_modules/.bin/ava

If the current behavior is a bug, please provide the steps to reproduce.

mkdir /tmp/test
cd /tmp/test
yarn add koapi

What is the expected behavior?

/tmp/test/node_modules/.bin/knex /tmp/test/node_modules/.bin/ava should be created.

Please mention your node.js, yarn and operating system version.

Node.js 7.1.0
yarn 0.16.1
macOS Sierra

[wyze]

Duplicate #760 and was fixed by #1210.