unrecognized command line option '-stdlib=libc++'

[foonlyboy]

On macos 10.11.6
with ruby 2.6.1 from macports

gem update sassc (from 2.0.0 to 2.0.1)
fails with:
c++: error: unrecognized command line option '-stdlib=libc++'

Workaround:
sudo env CXX=/opt/local/bin/clang gem update sassc

• macports compiles ruby with /opt/local/bin/clang
• gem defaults to option: '-stdlib=libc++'
• sassc uses c++ as the compiler (instead of clang or the gem default)
• c++ on my machine is linked to gcc (which does not understand -stdlib=libc++)

I suspect:

• you take the compiler options from the gem defaults
• you preset the compiler to be 'c++' (not from the gem defaults)

Setting env CXX to /opt/local/bin/clang fixed the problem for me (see Workaround above)

Regards,
~eike