Missing C++ header <__debug> after updating OSX Command Line Tools 6.3

Question

After updating to Command Line Tools 6.3 from the App Store, programs including <vector> or <iterator> which internally include <__debug> will cause file not found error as follows. The cpp is nothing interesting but includes in one of the included headers.

c++ -O3 -I/Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers -L/Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/build/binaries/clusterStaticLibrary /Users/farleylai/Documents/dev/git/ESMS/Optimizer/build/StreamIt/FIR/511/512/combined_threads.cpp -o streamit -lcluster -lpthread -lstdc++
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/build/StreamIt/FIR/511/512/combined_threads.cpp:9:
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers/node_server.h:22:
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers/thread_info.h:20:
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers/connection_info.h:19:
/Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers/socket_holder.h:43:25: warning: delete called on 'mysocket' that is abstract but has non-virtual destructor
      [-Wdelete-non-virtual-dtor]
    if (!is_mem_socket) delete sock;
                        ^
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/build/StreamIt/FIR/511/512/combined_threads.cpp:9:
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers/node_server.h:22:
In file included from /Users/farleylai/Documents/dev/git/ESMS/Optimizer/../StreamIt/src/cluster/headers/thread_info.h:26:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/vector:265:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/__bit_reference:15:
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/algorithm:641:10: fatal error: '__debug' file not found
#include <__debug>
         ^

Any ideas to fix this? I don't expect to specify any additional C++ flags.

Thanks.

PS: MacBook pro on OSX 10.10.3

Updates:

The issue is verified by Apple on their developer's forum. In Command Line Tools 6.2, the inclusion of __debug is conditionally guarded as follows but not in 6.3.

#ifdef _LIBCPP_DEBUG
#   include <__debug>
#else
#   define _LIBCPP_ASSERT(x, m) ((void)0)
#endif

And libcxx people talked about removing the guards of __debug here. It feels like __debug never exists on OSX.

Answer 1

Downgrade the Command Line Tools to 6.2 via Apple's Developer Download Page.

Be careful to download the correct version for your OS X:

• OS X 10.10 commandlinetoolsosx10.10forxcode6.2.dmg
• OS X 10.9 commandlinetoolsosx10.9forxcode6.2.dmg

This works because the inclusion of __debug is conditionally guarded as follows in Command Line Tools 6.2 but not in 6.3.

#ifdef _LIBCPP_DEBUG
#   include <__debug>
#else
#   define _LIBCPP_ASSERT(x, m) ((void)0)
#endif

In my opinion this is the safest way, because:

1. You don't compromise your toolchain
2. You can easily upgrade via the App Store when Apple fixes the issue
3. If you add a file manually you have to delete it later or more problems could occur

Update - 21.04.2015

Problem fixed by Apple. After installing Command Line Tools 6.3.1 everything works as expected!