From: Jack Howarth <howarth@br...> - 2011-10-11 23:57:35
When Xcode 4.2 is released, we will need to be alert for new build problems
on 10.7 stable. The Xcode 4.2's clang compilers now use the new TLS support
in the darwin11 SDK (which wasn't the case for Xcode 4.1). This has already
been discovered to break libmpfr4. If your package fails to pass it's testsuite
under Xcode 4.2 due to the TLS support malfunctioning, this can be avoided
by either passing --disable-thread-safe to configure or if that isn't available
using -mmacosx-version-min=10.6 on the compile flags. FYI.
ps Currently under Xcode 4.1, clang never provides TLS support (whereas llvm29
does and can be used to reproduce the problem under Lion).