How do I make Arduino IDE use a specific version of GCC in Debian? Using Raspbian Stretch.

I installed gcc-4.9 with specified version. Then I installed arduino (2.1.0.5) which in turn pulled gcc 4.6. When I try to compile Marlin in it, it says 


  Marlin requires C++11 support (gcc >= 4.7, Arduino IDE >= 1.6.8).
  Please upgrade your toolchain.


How do I make Arduino IDE use the correct version of GCC?
As Majenko pointed out, I should have used a tarball from the official site instead of the repositories. Which makes me wonder why that package wasn't deprecated or something...