build gem5 error: gcc version 4.7 or newer required.

[Jason Von]

hi all,

I follow the instruction of start page(https://gem5-gpu.cs.wisc.edu/wiki/start#build) ,and meet error as follow:

$ scons build/X86_VI_hammer_GPU/gem5.opt --default=X86 EXTRAS=../gem5-gpu/src:../gpgpu-sim/ PROTOCOL=VI_hammer GPGPU_SIM=True

scons: Reading SConscript files ...

Error: gcc version 4.7 or newer required.

       Installed version: 4.4.7

But I have already install gcc 4.8

$ gcc --version

gcc (Ubuntu 4.8.4-2ubuntu1~14.04) 4.8.4

Whats more, i used install gcc by apt-get, so i have 2 gcc

fsj@fsj-Lenovo:/usr/bin$ ll | grep gcc

-rwxr-xr-x  1 root root         428  5月  7  2006 c89-gcc*

-rwxr-xr-x  1 root root         454  4月 11  2011 c99-gcc*

lrwxrwxrwx  1 root root           7 11月 30 22:04 gcc -> gcc-4.8*

-rwxr-xr-x  1 root root      220412  3月 20  2014 gcc-4.4*

-rwxr-xr-x  1 root root      720324  5月 15  2015 gcc-4.8*

......

Anyone know how to solve it?

thanks a lot!

Jason

[Joel Hestness]

Hi Jason,

  It seems your environment is probably pointing to an incorrect gcc. You can check this by running 'which gcc' and 'which g++' to see if maybe your PATH variable is incorrect.

  One way to get around this without having to debug the environment settings is to explicitly specify which gcc/g++ to use when building gem5. You can do this by adding 'CC=/path/to/your/gcc-4.8 CXX=/path/to/your/g++-4.8' to your build command line.

  Joel

--

  Joel Hestness
  PhD Candidate, Computer Architecture
  Dept. of Computer Science, University of Wisconsin - Madison
  http://pages.cs.wisc.edu/~hestness/

[Jason Von]

Hi Joel, 

I got it.

In path /usr/bin/, gcc(soft link file ) pointing to gcc-4.8, while g++ pointing to g++4.4, I remove old version g++ and create g++ pointing to g++-4.8. Then , build success.

it is not the problem of environment , maby error info should modifyed into: "gcc and g++ version 4.7 or newer required" :)

Thank you again!

Jason