make:execvp:g ++:权限被拒绝

我正在尝试therubyracer在Amazon Linux AMI(~cenOS)上安装.

[www@ip-10-0-0-125 root]$ gem install therubyracer
Fetching: libv8-3.16.14.3-x86_64-linux.gem (100%)
Successfully installed libv8-3.16.14.3-x86_64-linux
Building native extensions.  This could take a while...
ERROR:  Error installing therubyracer:
    ERROR: Failed to build gem native extension.

    /home/www/.rvm/rubies/ruby-2.1.1/bin/ruby extconf.rb
checking for main() in -lpthread... yes
creating Makefile

make "DESTDIR=" clean

make "DESTDIR="
compiling handles.cc
make: execvp: g++: Permission denied
make: *** [handles.o] Error 127

Permission denied @ dir_chdir - /root

Gem files will remain installed in /home/www/.rvm/gems/ruby-2.1.1/gems/therubyracer-0.12.1 for inspection.
Results logged to /home/www/.rvm/gems/ruby-2.1.1/extensions/x86_64-linux/2.1.0/therubyracer-0.12.1/gem_make.out
[www@ip-10-0-0-125 root]$

我不知道该尝试什么..我在服务器上手动安装它gem install therubyracer.我先尝试过libv8,许多不同的版本和版本组合.

我www在~目录中的用户下运行它.

谢谢