If running in a Linux version which says it does not support GLSL 3.30, set these two environment variables which will tell the drivers to use a compatibility mode. This can also be done in code I believe but have not yet looked into both detection of the available GLSL versions and how best to handle use of compatibility modes.
export MESA_GL_VERSION_OVERRIDE=3.3
export MESA_GLSL_VERSION_OVERRIDE=330