https://bugs.freedesktop.org/show_bug.cgi?id=68451
--- Comment #7 from Emil Velikov emil.l.velikov@gmail.com --- (In reply to comment #5)
glsl_parser.cpp:2603:41: error: 'scanner' was not declared in this scope
Arch uses Bison 3, thus you might need to apply one or all of the following.
eb7c8c7fb6e49a04f3fe84a6d438160dc4a14ac0 f043381334a0760ec118d07b6fb7785b5692572a de917b4c4c4dfc949d5f8e3d9eb2dd48b63a3de5 6d2a9220b832d9a0c0cf35fcc5b9de1542af267d 5ffa28df4e4cc22481b4ed41c78632f35765f41d