emulator GL translator errors during autopilot tests

I'm also seeing this when running the emulator inside an openstack instance:

sdk/emulator/opengl/host/libs/Translator/GLES_V2/GLESv2Imp.cpp:glReadPixels:1610 error 0x500

That happens every time I try to capture the screen using mirscreencast or phablet-screenshot.

GL seems to be wired up correctly:

ubuntu@ev-testing:~$ xvfb-run --server-args="-screen 0 1024x768x24 +extension GLX" glxinfo
name of display: :99
display: :99 screen: 0
direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.4
server glx extensions:
    GLX_ARB_multisample, GLX_EXT_import_context, GLX_EXT_texture_from_pixmap,
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_MESA_copy_sub_buffer,
    GLX_OML_swap_method, GLX_SGIS_multisample, GLX_SGIX_fbconfig,
    GLX_SGIX_pbuffer, GLX_SGI_make_current_read
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_create_context, GLX_ARB_create_context_profile,
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float,
    GLX_ARB_framebuffer_sRGB, GLX_ARB_get_proc_address, GLX_ARB_multisample,
    GLX_EXT_buffer_age, GLX_EXT_create_context_es2_profile,
    GLX_EXT_fbconfig_packed_float, GLX_EXT_framebuffer_sRGB,
    GLX_EXT_import_context, GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info,
    GLX_EXT_visual_rating, GLX_INTEL_swap_event, GLX_MESA_copy_sub_buffer,
    GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer,
    GLX_MESA_swap_control, GLX_OML_swap_method, GLX_OML_sync_control,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
    GLX_SGIX_visual_select_group, GLX_SGI_make_current_read,
    GLX_SGI_swap_control, GLX_SGI_video_sync
GLX version: 1.4
GLX extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context,
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_MESA_copy_sub_buffer, GLX_MESA_multithread_makecurrent,
    GLX_OML_swap_method, GLX_SGIS_multisample, GLX_SGIX_fbconfig,
    GLX_SGIX_pbuffer, GLX_SGI_make_current_read
OpenGL vendor string: VMware, Inc.
OpenGL renderer string: Gallium 0.4 on llvmpipe (LLVM 3.5, 256 bits)
OpenGL version string: 3.0 Mesa 10.2.6
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:
    GL_AMD_conservative_depth, GL_AMD_draw_buffers_blend,
    GL_AMD_seamless_cubemap_per_texture, GL_AMD_shader_trinary_minmax,
    GL_ANGLE_texture_compression_dxt3, GL_ANGLE_texture_compression_dxt5,
    GL_APPLE_packed_pixels, GL_APPLE_vertex_array_object,
    GL_ARB_ES2_compatibility, GL_ARB_blend_func_extended,
    GL_ARB_clear_buffer_object, GL_ARB_color_buffer_float,
    GL_ARB_conservative_depth, GL_ARB_copy_buffer, GL_ARB_debug_output,
    GL_ARB_depth_buffer_float, GL_ARB_depth_clamp, GL_ARB_depth_texture,
    GL_ARB_draw_buffers, GL_ARB_draw_buffers_blend,
    GL_ARB_draw_elements_base_vertex, GL_ARB_draw_instanced,
    GL_ARB_explicit_attrib_location, GL_ARB_fragment_coord_conventions,
    GL_ARB_fragment_program, GL_ARB_fragment_program_shadow,
    GL_ARB_fragment_shader, GL_ARB_framebuffer_object,
    GL_ARB_framebuffer_sRGB, GL_ARB_get_program_binary,
    GL_ARB_half_float_pixel, GL_...