The helper class com.jogamp.opengl.util.glsl.ShaderProgram sometimes ignores the specified PrintStream and dumps errors to System.err. The methods in particular that exhibit this behavior are: ShaderProgram.replaceShader() and ShaderProgram.link() when they call ShaderUtil.isProgramLinkStatusValid().
Thank you John.
Can you provide a patch (git pull request or git patch)
which I can merge ?
Since you seem to have analyzed this issue thoroughly .. you may also fix it?