No I'm using 1.7 to execute it and compile other things. So I'm in 1.7 mode except during this build : 

$ /usr/libexec/java_home -V
Matching Java Virtual Machines (4):
    1.7.0_45, x86_64:	"Java SE 7"	/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home
    1.7.0_09, x86_64:	"Java SE 7"	/Library/Java/JavaVirtualMachines/jdk1.7.0_09.jdk/Contents/Home
    1.6.0_32-b05-420, x86_64:	"Java SE 6"	/Library/Java/JavaVirtualMachines/1.6.0_32-b05-420.jdk/Contents/Home
    1.6.0_32-b05-420, i386:	"Java SE 6"	/Library/Java/JavaVirtualMachines/1.6.0_32-b05-420.jdk/Contents/Home