/usr/share/bug/libosmesa6-dev/script is in libosmesa6-dev 10.3.2-1+deb8u1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | #!/bin/sh
SERVER_BUG_SCRIPT=/usr/share/bug/xserver-xorg-core/script
exec >&3
echo "glxinfo:"
echo "--------"
if [ -z "$DISPLAY" ]; then
    echo "DISPLAY is not set."
else
    if which glxinfo >/dev/null 2>&1; then
        glxinfo
    else
        echo "glxinfo is not available (missing mesa-utils package)."
    fi
fi
echo
if [ -x "$SERVER_BUG_SCRIPT" ]; then
    $SERVER_BUG_SCRIPT 3>&1
else
    echo "$SERVER_BUG_SCRIPT not available"
fi
 |