Vagrant: rvmダウンロードの進行状況の出力が破損しています

私はbashシェルスクリプトを介したプロビジョニングに取り組んでいますが、1つのステップで奇妙な出力動作が発生しています。

具体的には、RVMのインストール手順は次のとおりです。

sudo -u vagrant -H sh -c "\curl -sSL https://get.rvm.io | bash -s stable --rails"

これにより、次の出力が生成されます。最初はコーシャですが、通常はプログレスバーが表示されるフェーズでは、文字が個別の印刷アクションとしてストリーミングされているかのように、各文字に独自の行がほとんどあります。

==> default: Downloading https://github.com/wayneeseguin/rvm/archive/stable.tar.gz
==> default: Installing RVM to /home/vagrant/.rvm/
==> default:     Adding rvm PATH line to /home/vagrant/.profile /home/vagrant/.bashrc /home/vagrant/.zshrc.
==> default:     Adding rvm loading line to /home/vagrant/.bash_profile /home/vagrant/.zlogin.
==> default: Installation of RVM in /home/vagrant/.rvm/ is almost complete:
==> default:   * To start using RVM you need to run `source /home/vagrant/.rvm/scripts/rvm`
==> default:     in all your open shell windows, in rare cases you need to reopen all shell windows.
==> default: # Administrator,
==> default: #
==> default: #   Thank you for using RVM!
==> default: #   We sincerely hope that RVM helps to make your life easier and more enjoyable!!!
==> default: #
==> default: # ~Wayne, Michal & team.
==> default: In case of problems: http://rvm.io/help and https://twitter.com/rvm_io
==> default: rvm 1.25.27 (stable) by Wayne E. Seguin <[email protected]>, Michal Papis <[email protected]> [https://rvm.io/]
==> default: Searching for binary rubies, this might take some time.
==> default: No binary rubies available for: ubuntu/14.04/i386/ruby-2.1.2.
==> default: Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
==> default: Checking requirements for ubuntu.
==> default: Requirements installation successful.
==> default: Installing Ruby from source to: /home/vagrant/.rvm/rubies/ruby-2.1.2, this may take a while depending on your cpu(s)...
==> default: ruby-2.1.2 - #downloading ruby-2.1.2, this may take a while depending on your connection...
==> default:  
==> default:  
==> default: %
==> default:  
==> default: T
==> default: o
==> default: t
==> default: a
==> default: l
==> default:  
==> default:  
==> default:  
==> default:  
==> default: %
==> default:  
==> default: R
==> default: e
==> default: c
==> default: e
==> default: i
==> default: v
==> default: e
==> default: d % Xferd  Average Speed   Time    Time     Time  Current
==> default:                                  Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
==> default:  
==> default:  
==> default: 0
==> default:  
==> default:  
==> default:  
==> default:  
==> default:  
==> default: 0
==> default:  
==> default:    0     0    0     0      0      0 --:--:--  0:00:01 --:--:--     0
  0     0    0     0    0     0      0      0 --:--:--  0:00:02 --:--:--     0
  0     0    0     0    0     0      0      0 --:--:--  0:00:03 --:--:--     0
  0     0    0     0    0     0      0      0 --:--:--  0:00:04 --:--:--     0
==> default:  
==> default:  
==> default: 0
==> default:  
==> default:  
==> default:  
==> default:  
==> default:  
==> default: 0
==> default:  
==> default:  
==> default:  
==> default:  
==> default: 0
==> default:  
==> default:  
  0     0    0     0    0     0      0      0 --:--:--  0:00:05 --:--:--     0
==> default:  
==> default:  
==> default: 8
==> default:  
==> default: 1
==> default: 1
==> default: .
==> default: 4
==> default: M
==> default:  
==> default:  
==> default:  
==> default:  
==> default: 8
==> default:  
==> default:  
==> default: 9
==> default: 6
==> default: 1
==> default: k
==> default:  
==> default:  
==> default:  
==> default:  
==> default: 0
==> default:  
==> default:     0   146k      0  0:01:20  0:00:06  0:01:14  237k
==> default:  
==> default: 31 11.4M   31 3694k    0     0   488k      0  0:00:23  0:00:07  0:00:16  916k
==> default:  
==> default: 8
==> default: 3
==> default:  
==> default: 1
==> default: 1
==> default: .
==> default: 4
==> default: M
==> default:  
==> default:  
==> default:  
==> default: 8
==> default: 3
==> default:  
==> default: 9
==> default: 7
==> default: 6
==> default: 1
==> default: k
==> default:  
==> default:    0     0  1141k      0  0:00:10  0:00:08  0:00:02 2429k
==> default: 1
==> default: 0
==> default: 0
==> default:  
==> default: 1
==> default: 1
==> default: .
==> default: 4
==> default: M
==> default:   100 11.4M    0     0  1325k      0  0:00:08  0:00:08 --:--:-- 3558k
==> default: ruby-2.1.2 - #extracting ruby-2.1.2 to /home/vagrant/.rvm/src/ruby-2.1.2
==> default: ...
==> default: ruby-2.1.2 - #configuring

これはおそらくhttps://github.com/mitchellh/vagrant/issues/471に関連しているようですが、その問題は異なって現れました（文字のセグメント化ではなく行の重複）。

環境：
Vagrant 1.6.2
Linux Mint 16（ペトラ）