Unable to add three.dart package from their Git repository - dart

Question

I tried adding the three/three.dart package from their Git repository to my project. I did that as mentioned here. But running pub get from the editor gives the following error:
Pub get failed, [1] Resolving dependencies... (0.1s)
Git error. Command: git fetch
fatal: Not a git repository (or any of the parent directories): .git
../../../../../../mnt/data/b/build/slave/dart-editor-linux-stable/build/dart/sdk/lib/_internal/pub/lib/src/git.dart 47 run.<fn>
dart:isolate _RawReceivePortImpl._handleMessage
This is an unexpected error. Please run
pub --trace 'get'
and include the results in a bug report on http://dartbug.com/new.
** Warning: Application may fail to run since packages did not get installed.Try running pub get again. **
Pub get failed, [1] Resolving dependencies... (0.1s)
Git error. Command: git fetch
fatal: Not a git repository (or any of the parent directories): .git
../../../../../../mnt/data/b/build/slave/dart-editor-linux-stable/build/dart/sdk/lib/_internal/pub/lib/src/git.dart 47 run.<fn>
dart:isolate _RawReceivePortImpl._handleMessage
This is an unexpected error. Please run
pub --trace 'get'
and include the results in a bug report on http://dartbug.com/new.
**
Warning: Application may fail to run since packages did not get installed.Try running pub get again. **
I do have git installed on my system. I run Ubuntu 14.04 if that's relevant.
Edit:
I tried pub --trace get and got this:
Resolving dependencies...
Git error. Command: git fetch
fatal: Not a git repository (or any of the parent directories): .git
This was followed by a long log message.
Here is pubspec.yaml file:
dependencies:
browser: any
three:
git:
url: 'git://github.com/threeDart/three.dart.git'
Got it to work finally. I specified the version along with the URL to the Git repo. Here is my final pubspec:
dependencies:
browser: any
three:
git: git://github.com/threeDart/three.dart.git
version: '>=0.2.5+1 <0.3.0'

Answer 1

I had to specify the version range for the package along with the link to the git repository.
dependencies:
browser: any
three:
git: git://github.com/threeDart/three.dart.git
version: '>=0.2.5+1 <0.3.0'