OS* X Lion and Xcode 4.x are supported in 12.1 versions of the compiler, aka "Composer XE 2011 SP1, Update 6" aka 12.1.0.038 build 20110817 released 24 August 2011. Please read the Release Notes, Requirements for your compiler version to find the supported versions of OS and Xcode.
12.0, 11.1 and older are not supported on Lion.
At this time Intel does not officially support our compilers on Mac OS* X 10.7
and/or integration into Xcode* 4.1.
Compilers versions 11.1 and
older are known to NOT work under Lion, and these older compilers will
not be updated to work for Lion.
A future update of the 12.x compiler will support Lion, but the currently released 12.0 Update 4 also does NOT support Lion.
Do not upgrade to Lion if you need a working Intel compiler until we officially support Lion.
More information is published