setup_vcpp.cmd bug

[screig]

I believe if you do not have VS12 but VS11 this batch file falls over:

• installing source package 'rClr' ...
  warning: Path to the Mono SDK not found by querying the Windows registry. Mono support will be disabled
  R_HOME=C:/PROGRA1/R/R-321.1
  'VSCOMNTOOLS' is not recognized as an internal or external command,
  operable program or batch file.
  ERROR: setup_vcpp cannot determine the location of the VS Common Tools folder.
  'lib' is not recognized as an internal or external command,
  operable program or batch file.
  'lib' is not recognized as an internal or external command,
  operable program or batch file.
  'lib' is not recognized as an internal or external command,
  operable program or batch file.
  Warning: running command 'sh ./configure.win' had status 1
  ERROR: configuration failed for package 'rClr'
• removing 'C:/_CODE/R/Library/rClr'

Here is a snippet of my environment variables:

VCINSTALLDIR=C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC
VS100COMNTOOLS=C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\To
VS110COMNTOOLS=C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\To
VSINSTALLDIR=C:\Program Files (x86)\Microsoft Visual Studio 11.0
windir=C:\Windows
WindowsSdkDir=C:\Program Files (x86)\Windows Kits\8.0
WindowsSdkDir_35=C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\

I believe this line (3) is failing:

@if "%VSCOMNTOOLS%"=="" VSCOMNTOOLS=%VS110COMNTOOLS%