glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as
"130". Mesa will not really implement all the features of the given language version
if it's higher than what's normally reported. (for developers only)
-<li>MESA_GLSL_CACHE_DISABLE - if set, disables the GLSL shader cache
+<li>MESA_GLSL_CACHE_DISABLE - if set to `true`, disables the GLSL shader cache
<li>MESA_GLSL_CACHE_MAX_SIZE - if set, determines the maximum size of
the on-disk cache of compiled GLSL programs. Should be set to a number
optionally followed by 'K', 'M', or 'G' to specify a size in
home directory.
<li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a>
<li>MESA_NO_MINMAX_CACHE - when set, the minmax index cache is globally disabled.
+<li>MESA_SHADER_CAPTURE_PATH - see <a href="shading.html#capture">Capturing Shaders</a></li>
+<li>MESA_SHADER_DUMP_PATH and MESA_SHADER_READ_PATH - see <a href="shading.html#replacement">Experimenting with Shader Replacements</a></li>
</ul>