babel-plugin-feature-flags name collision in 2.5.1 with fastboot

[davidpett]

When updating to version 2.5.1 and running ember s I received the following error:

File: modules/ember-data/adapter.js
The Broccoli Plugin: [Babel] failed with:
ReferenceError: The plugin "babel-plugin-feature-flags" collides with another of the same name

After some digging, @pangratz found that because I am using ember-cli-fastboot there is a collision in the plugins. You can reproduce the issue with these steps:

ember new abcd
cd abcd
ember build # works as expected

ember install ember-cli-fastboot
ember build # throws ReferenceError: The plugin "babel-plugin-feature-flags" collides with another of the same name

[fivetanley]

This should be fixed once we change the approach in ember-cli-fastboot ember-fastboot/ember-cli-fastboot#145

[rwjblue]

#4328 seems like the correct fix for ember-data itself (though I do think that fastboot PR is also the correct direction).

[davidpett]

To be able to use this fix, do i need to run on master? or will release include it?

[rwjblue]

Release will include it, but I don't think it's been cherry picked yet.