user48357: 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?

user48357: 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...

48357: <p>Using Raspbian Stretch.</p>

<p>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 <a href="https://reprap.org/wiki/Marlin" rel="nofollow noreferrer">Marlin</a> in it, it says </p>

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

<p>How do I make Arduino IDE use the correct version of GCC?</p>
 48357: <p>As Majenko <a href="https://arduino.stackexchange.com/questions/54792/how-do-i-make-arduino-ide-use-a-specific-version-of-gcc-in-debian#comment115148_54792">pointed out</a>, I should have used a tarball from the <a href="https://www.arduino.cc/en/Main/Software" rel="nofollow noreferrer">official site</a> instead of the repositories. Which makes me wonder why that package wasn't deprecated or something...</p>
