[R-SIG-Mac] there is a trouble after updating to Xcode 4.3.2

[Epi Metheus]

Hello the R MacOSX community,

When installing libamtrack by compiling source, there is an error :

* installing *source* package ‘libamtrack’ ...
** package ‘libamtrack’ correctement décompressé et sommes MD5 vérifiées
checking for gsl-config... no
configure: error: gsl-config not found, is GSL installed?
ERROR: configuration failed for package ‘libamtrack’
* removing
‘/Library/Frameworks/R.framework/Versions/2.15/Resources/library/libamtrack’

This might be connected to the fact that the last Xcode is now installed
in the /Applications directory and has removed the /Developper directory
Thank you for any help !