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

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!

Temporarily create the missing __debug file where _LIBCPP_ASSERT is defined as in Command Line Tools 6.2 for OS X.

echo '#define _LIBCPP_ASSERT(x, m) ((void)0)' | sudo tee -a /Library/Developer/CommandLineTools/usr/include/c++/v1/__debug > /dev/null

Remove the temporary file after the build finished.

sudo rm /Library/Developer/CommandLineTools/usr/include/c++/v1/__debug

Warning!!! This is a hack, use at your own risk!!! This work-around is only meant as a temporary fix until Apple provides an update to the command-line tools.

OK, here we go: Create the file yourself and put the following content into it:

#ifndef _LIBCPP_ASSERT#define _LIBCPP_ASSERT(...) ((void)0)#endif

This seems to work for me, but it is certainly not the right thing to do. Make sure the file is located at the right place /Library/Developer/CommandLineTools/usr/include/c++/v1/__debug with the right owner/permissions.