Comment # 6 on bug 97852 from Michel Dänzer

A shader program fails to link, see below. This may be an Unreal Engine
(editor) bug, reassigning to the GLSL compiler for now.

839119 @4 glLinkProgram(program = 3018)
839119: warning: link failed
839119: warning: error: vertex shader output `out_TEXCOORD0' specifies
noperspective interpolation qualifier, but fragment shader input specifies no
interpolation qualifier

Mesa: User error: GL_INVALID_OPERATION in glUseProgram(program 3018 not linked)
[more errors]