feature is not currently supported by SCons build.
This is controlled via following environment variables:
+</p>
<ul>
<li><b>MESA_SHADER_DUMP_PATH</b> - path where shader sources are dumped
<li><b>MESA_SHADER_READ_PATH</b> - path where replacement shaders are read
When both are set, these paths should be different so the dumped shaders do
not clobber the replacement shaders. Also, the filenames of the replacement shaders
should match the filenames of the corresponding dumped shaders.
-</p>
<h3 id="capture">Capturing Shaders</h3>