These days, most driver debug output happens via stderr, not stdout. Some applications (such as Xephyr) also appear to close stdout which makes these messages go nowhere.
8892a6b mesa: Make _mesa_print_arrays use stderr.
src/mesa/main/varray.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
Upstream: cgit.freedesktop.org