With Xcode 5.1, Apple has discontinued support for Garbage Collection. After configuring, all attempts to compile Tk (or Tk based extension) dies on the first file with:

error: garbage collection is no longer supported
make[1]: *** [tkStubLib.o] Error 1
make: *** [tcltk] Error 2

Apple recommends transitioning to Automatic Reference Counting (ARC). The process is described at:


Essentially the memory access routines that trade in Native Cocoa objects need a rewrite to support the new API. (As do extensions like Canvas3d which also trade in native Cocoa objects.)

No version of Tcl or Tk will compile on OSX with Xcode 5.1 or above until this is fixed. Already compiled binaries seem not to be affected.