mkvtoolnix 7.7.0 failed to build on 10.10.2

[guoxiao]

mkvtoolnix 7.7.0 failed to build, which complains Boost::FileSystem is not found. But I have installed boost.
Gist-logs is as following:
https://gist.github.com/anonymous/eb736172dac19e5e93b7

I try to extract the source code and run ./configure with the same arguments. It can find boost correctly. So I think it may be related to homebrew itself.

[jacknagel]

The actual thing that causes the failure in configure's boost usability test is:

In file included from /Applications/Xcode-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstddef:36:
/Applications/Xcode-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__config:227:20: error: cannot combine with previous 'char16_t' declaration specifier
typedef __char16_t char16_t;
                   ^
/Applications/Xcode-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__config:228:20: error: cannot combine with previous 'char32_t' declaration specifier
typedef __char32_t char32_t;
                   ^

so it seems like an incompatibility (or bug) with the latest libc++ headers.

[guoxiao]

I've found the problem. I installed ccache and clang++ is a symbolic link to ccache, which caused the problem.
I removed the symbolic link, and it works well now. Thanks for your help.