Ubuntu chromebook上带kivy的黑色/透明屏幕

当试图运行一个简单的hello world程序时，kivy将显示一个黑色或透明（下面所有内容的可视副本）屏幕。在Acer Chromebook C740上使用Ubuntu 14.04。与此类似，但使用crouton而不是dual boot，使用Ubuntu而不是xfce

[INFO   ] [Logger      ] Record log in /home/wxv/.kivy/logs/kivy_16-03-23_0.txt
[INFO   ] [Kivy        ] v1.9.1
[INFO   ] [Python      ] v2.7.6 (default, Jun 22 2015, 17:58:13) 
[GCC 4.8.2]
[INFO   ] [Factory     ] 179 symbols loaded
[DEBUG  ] [Cache       ] register <kv.lang> with limit=None, timeout=None
[DEBUG  ] [Cache       ] register <kv.image> with limit=None, timeout=60
[DEBUG  ] [Cache       ] register <kv.atlas> with limit=None, timeout=None
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_gif, img_sdl2, img_pil (img_ffpyplayer ignored)
[DEBUG  ] [Cache       ] register <kv.texture> with limit=1000, timeout=60
[DEBUG  ] [Cache       ] register <kv.shader> with limit=1000, timeout=3600
[INFO   ] [Text        ] Provider: sdl2
[DEBUG  ] [App         ] Loading kv <./my.kv>
[DEBUG  ] [App         ] kv <./my.kv> not found
[DEBUG  ] [Window      ] Ignored <egl_rpi> (import error)
[INFO   ] [OSC         ] using <multiprocessing> for socket
[INFO   ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
[INFO   ] [GL          ] OpenGL version <3.0 Mesa 10.1.3>
[INFO   ] [GL          ] OpenGL vendor <Intel Open Source Technology Center>
[INFO   ] [GL          ] OpenGL renderer <Mesa DRI Intel(R) Broadwell >
[INFO   ] [GL          ] OpenGL parsed version: 3, 0
[INFO   ] [GL          ] Shading version <1.30>
[INFO   ] [GL          ] Texture max size <8192>
[INFO   ] [GL          ] Texture max units <32>
[DEBUG  ] [Shader      ] Fragment compiled successfully
[DEBUG  ] [Shader      ] Vertex compiled successfully
[DEBUG  ] [ImageSDL2   ] Load </usr/lib/python2.7/dist-packages/kivy/data/glsl/default.png>
[INFO   ] [Window      ] auto add sdl2 input provider
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/unfonts-core> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/msttcorefonts> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/freefont> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/wqy> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/ttf-dejavu> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/droid> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/liberation> in path list
[DEBUG  ] [Resource    ] add </usr/share/fonts/truetype/dejavu> in path list
[DEBUG  ] [Resource    ] add </usr/local/share/fonts> in path list
[DEBUG  ] [Resource    ] add </usr/lib/python2.7/dist-packages/kivy/data/fonts> in path list
[DEBUG  ] [Base        ] Create provider from mouse
[DEBUG  ] [Base        ] Create provider from probesysfs
[DEBUG  ] [ProbeSysfs  ] using probesysfs!
[INFO   ] [Base        ] Start application main loop
[INFO   ] [GL          ] NPOT texture support is available
[DEBUG  ] [Atlas       ] Load </usr/lib/python2.7/dist-packages/kivy/data/../data/images/defaulttheme.atlas>
[DEBUG  ] [Atlas       ] Need to load 1 images
[DEBUG  ] [Atlas       ] Load </usr/lib/python2.7/dist-packages/kivy/data/../data/images/defaulttheme-0.png>
[DEBUG  ] [ImageSDL2   ] Load </usr/lib/python2.7/dist-packages/kivy/data/../data/images/defaulttheme-0.png>

[INFO][Logger]记录登录/home/wxv/.kivy/logs/kivy_16-03-23_0.txt
[INFO][Kivy]v1.9.1
[INFO][Python]v2.7.6（默认，2015年6月22日，17:58:13）
[GCC 4.8.2]
[信息][工厂]加载了179个符号
[DEBUG][Cache]寄存器，限制=None，超时=None
[DEBUG][Cache]寄存器，限制=None，超时=60
[DEBUG][Cache]寄存器，限制=None，超时=None
[信息][图像]提供商：img_-tex、img_-dds、img_-gif、img_-sdl2、img_-pil（img_-ffpyplayer忽略）
[DEBUG][Cache]寄存器，限制为1000，超时为60
[DEBUG][Cache]寄存器，限制为1000，超时为3600
[信息][文本]提供商：sdl2
[调试][应用]加载千伏
[调试][应用程序]未找到
[调试][窗口]已忽略（导入错误）
[信息][OSC]用于插座
[INFO][Window]提供程序：sdl2（['Window\u egl\u rpi']已忽略）
[信息][GL]OpenGL版本
[信息][GL]OpenGL供应商
[INFO][GL]OpenGL渲染器
[信息][GL]OpenGL解析版本：3,0
[信息][GL]明暗处理版本
[信息][GL]纹理最大大小
[信息][GL]纹理最大单位
[DEBUG][Shader]片段已成功编译
[调试][着色器]顶点已成功编译
[DEBUG][ImageSDL2]加载
[信息][窗口]自动添加sdl2输入提供程序
[信息][窗口]不允许使用虚拟键盘，单模，未对接
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[调试][资源]加载项路径列表
[DEBUG][Base]从鼠标创建提供程序
[DEBUG][Base]从probesysfs创建提供程序
[DEBUG][ProbeSysfs]使用ProbeSysfs！
[INFO][Base]启动应用程序主循环
[INFO][GL]提供NPOT纹理支持
[调试][Atlas]加载
[DEBUG][Atlas]需要加载1个图像
[调试][Atlas]加载
[DEBUG][ImageSDL2]加载