Problems reported on NetBSD:
llvm[4]: Linking Debug+Asserts executable lldb /tmp/build-llvm/Debug+Asserts/lib/liblldb.so: undefined reference to `llvm::createObjCARCExpandPass()' /tmp/build-llvm/Debug+Asserts/lib/liblldb.so: undefined reference to `llvm::createObjCARCOptPass()' /tmp/build-llvm/Debug+Asserts/lib/liblldb.so: undefined reference to `llvm::createObjCARCAPElimPass()' /tmp/build-llvm/Debug+Asserts/lib/liblldb.so: undefined reference to `llvm::createObjCARCContractPass()' clang: error: linker command failed with exit code 1 (use -v to see invocation) /tmp/llvm/Makefile.rules:1434: recipe for target '/tmp/build-llvm/Debug+Asserts/bin/lldb' failed