docs: document MESA_EXTENSION_OVERRIDE env var

diff --git a/docs/envvars.html b/docs/envvars.html
index 7fd9fe7c0a83f48d8fe98405ace0a88f51fff79f..6d7a321da9fb577c39e87adaea57a314ec2c402b 100644 (file)
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -25,6 +25,9 @@ fragment programs (intended for developers only)
 <li>MESA_TNL_PROG - if set, implement conventional vertex transformation
 operations with vertex programs (intended for developers only).
 Setting this variable automatically sets the MESA_TEX_PROG variable as well.
+<li>MESA_EXTENSION_OVERRIDE - can be used to enable/disable extensions.
+A value such as "GL_EXT_foo -GL_EXT_bar" will enable the GL_EXT_foo extension
+and disable the GL_EXT_bar extension.
 </ul>
 
 <p>