changed default gcc version, now compiling problems - c++

Question

For an installation I had to change my default gcc compiler version. I had some compilation issues with the version I used so I downloaded several other versions via macports, and one of them worked for my installation finally.
I'm almost sure that the one I used before was gcc4.2, listed in my ports as: llvm-gcc42 .
In two other cases now I am facing compilation problems of c++ files. I'm not knowledgeable with c++, I'm using the compiler just for the compilation of some - mostly node.js - modules or now, a package for the atom editor.
Here is what I get, that leads me to the assumtion that something with the c++ compiler is not correct:
cc1plus: error: unrecognized command line option "-std=gnu++0x"
I could get rid of this in the first case by changing the default gcc version. But I cannot try several versions everytime.
So: Which is the gcc version I should use or is there anything else that could cause this? gcc5, the latest gives me the same..
In a specific case: Problem with installing termrk (module for the atom editor)
gcc --version
gcc (MacPorts gcc5 5.2.0_0) 5.2.0
[...]
There are two ways to install atom packages: Inside the editor with the gui and with the command line tool apm. Neither one works, but I get different error messages.
1. inside the gui:
> pty.js#0.2.13 install /private/var/folders/nl/2ppbw8fn0cjbw04pdqbxmqtr0000gn/T/apm-install-dir-115913-1105-1g6fykw/node_modules/Termrk/node_modules/pty.js
> node-gyp rebuild
CXX(target) Release/obj.target/pty/src/unix/pty.o
cc1plus: error: unrecognized command line option "-std=gnu++0x"
make: *** [Release/obj.target/pty/src/unix/pty.o] Error 1
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack at ChildProcess.onExit (/Applications/Atom.app/Contents/Resources/app/apm/node_modules/npm/node_modules/node-gyp/lib/build.js:269:23)
gyp ERR! stack at ChildProcess.emit (events.js:98:17)
gyp ERR! stack at Process.ChildProcess._handle.onexit (child_process.js:820:12)
gyp ERR! System Darwin 12.6.0
gyp ERR! command "node" "/Applications/Atom.app/Contents/Resources/app/apm/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /private/var/folders/nl/2ppbw8fn0cjbw04pdqbxmqtr0000gn/T/apm-install-dir-115913-1105-1g6fykw/node_modules/Termrk/node_modules/pty.js
gyp ERR! node -v v0.10.40
gyp ERR! node-gyp -v v2.0.2
gyp ERR! not ok
npm ERR! Darwin 12.6.0
npm ERR! argv "/Applications/Atom.app/Contents/Resources/app/apm/bin/node" "/Applications/Atom.app/Contents/Resources/app/apm/node_modules/npm/bin/npm-cli.js" "--globalconfig" "/Users/michael/.atom/.apm/.apmrc" "--userconfig" "/Users/michael/.atom/.apmrc" "install" "/private/var/folders/nl/2ppbw8fn0cjbw04pdqbxmqtr0000gn/T/d-115913-1105-1hg4ytj/package.tgz" "--target=0.30.7" "--arch=x64"
npm ERR! node v0.10.40
npm ERR! npm v2.13.3
npm ERR! code ELIFECYCLE
npm ERR! pty.js#0.2.13 install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the pty.js#0.2.13 install script 'node-gyp rebuild'.
npm ERR! This is most likely a problem with the pty.js package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! node-gyp rebuild
npm ERR! You can get their info via:
npm ERR! npm owner ls pty.js
npm ERR! There is likely additional logging output above.
npm ERR! Please include the following file with any support request:
npm ERR! /private/var/folders/nl/2ppbw8fn0cjbw04pdqbxmqtr0000gn/T/apm-install-dir-115913-1105-1g6fykw/npm-debug.log
1. In the terminal:
~ michael$ sudo apm install termrk
Installing termrk to /Users/michael/.atom/packages ✗
> pty.js#0.2.13 install /private/tmp/apm-install-dir-115913-1063-2zj63h/node_modules/Termrk/node_modules/pty.js
> node-gyp rebuild
shell-init: error retrieving current directory: getcwd: cannot access parent directories: Permission denied
shell-init: error retrieving current directory: getcwd: cannot access parent directories: Permission denied
node.js:844
var cwd = process.cwd();
^
Error: EACCES, permission denied
at Function.startup.resolveArgv0 (node.js:844:23)
at startup (node.js:58:13)
at node.js:935:3
npm ERR! Darwin 12.6.0
npm ERR! argv "/Applications/Atom.app/Contents/Resources/app/apm/bin/node" "/Applications/Atom.app/Contents/Resources/app/apm/node_modules/npm/bin/npm-cli.js" "--globalconfig" "/Users/michael/.atom/.apm/.apmrc" "--userconfig" "/Users/michael/.atom/.apmrc" "install" "/private/tmp/d-115913-1063-1cgkfyq/package.tgz" "--target=0.30.7" "--arch=x64"
npm ERR! node v0.10.40
npm ERR! npm v2.13.3
npm ERR! code ELIFECYCLE
npm ERR! pty.js#0.2.13 install: `node-gyp rebuild`
npm ERR! Exit status 8
npm ERR!
npm ERR! Failed at the pty.js#0.2.13 install script 'node-gyp rebuild'.
npm ERR! This is most likely a problem with the pty.js package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! node-gyp rebuild
npm ERR! You can get their info via:
npm ERR! npm owner ls pty.js
npm ERR! There is likely additional logging output above.
npm ERR! Please include the following file with any support request:
npm ERR! /private/tmp/apm-install-dir-115913-1063-2zj63h/npm-debug.log

Answer 1

That is a valid option for GCC 5.2 so if it says it's unrecognized then it means you are not using GCC 5.2.
You're probably still compiling with the old GCC 4.2 version.