linux garry's mod crashing on startup (blue loading screen)

hi there,
i’m on debian 9 “stretch” linux and the game just crashes when starting. i’ve tried everything i found and nothing works.
if somebody knows where crash logs are on linux, please help me.

greetings

edit: these are the console logs from steam when starting gmod:

This system supports the OpenGL extension GL_EXT_framebuffer_object.
This system supports the OpenGL extension GL_EXT_framebuffer_blit.
This system supports the OpenGL extension GL_EXT_framebuffer_multisample.
This system DOES NOT support the OpenGL extension GL_APPLE_fence.
This system supports the OpenGL extension GL_NV_fence.
This system supports the OpenGL extension GL_ARB_sync.
This system supports the OpenGL extension GL_EXT_draw_buffers2.
This system supports the OpenGL extension GL_EXT_bindable_uniform.
This system DOES NOT support the OpenGL extension GL_APPLE_flush_buffer_range.
This system supports the OpenGL extension GL_ARB_map_buffer_range.
This system supports the OpenGL extension GL_ARB_vertex_buffer_object.
This system supports the OpenGL extension GL_ARB_occlusion_query.
This system DOES NOT support the OpenGL extension GL_APPLE_texture_range.
This system DOES NOT support the OpenGL extension GL_APPLE_client_storage.
This system DOES NOT support the OpenGL extension GL_ARB_uniform_buffer.
This system supports the OpenGL extension GL_ARB_vertex_array_bgra.
This system supports the OpenGL extension GL_EXT_vertex_array_bgra.
This system supports the OpenGL extension GL_ARB_framebuffer_object.
This system DOES NOT support the OpenGL extension GL_GREMEDY_string_marker.
This system supports the OpenGL extension GL_ARB_debug_output.
This system supports the OpenGL extension GL_EXT_direct_state_access.
This system supports the OpenGL extension GL_NV_bindless_texture.
This system DOES NOT support the OpenGL extension GL_AMD_pinned_memory.
This system supports the OpenGL extension GL_EXT_framebuffer_multisample_blit_scaled.
This system supports the OpenGL extension GL_EXT_texture_sRGB_decode.
This system supports the OpenGL extension GL_NVX_gpu_memory_info.
This system DOES NOT support the OpenGL extension GL_ATI_meminfo.
This system supports the OpenGL extension GL_EXT_texture_compression_s3tc.
This system supports the OpenGL extension GL_EXT_texture_compression_dxt1.
This system DOES NOT support the OpenGL extension GL_ANGLE_texture_compression_dxt3.
This system DOES NOT support the OpenGL extension GL_ANGLE_texture_compression_dxt5.
This system supports the OpenGL extension GLX_EXT_swap_control_tear.
GL_NV_bindless_texture: DISABLED
GL_AMD_pinned_memory: DISABLED
GL_EXT_texture_sRGB_decode: AVAILABLE
GL_NVX_gpu_memory_info: AVAILABLE
GL_ATI_meminfo: UNAVAILABLE
GL_NVX_gpu_memory_info: Total Dedicated: 8388608, Total Avail: 8388608, Current Avail: 7546624
GL_MAX_SAMPLES_EXT: 32
IDirect3DDevice9::Create: BackBufWidth: 1920, BackBufHeight: 1080, D3DFMT: 3, BackBufCount: 1, MultisampleType: 0, MultisampleQuality: 0
GL sampler object usage: ENABLED
GL prefer MapBufferRange: NO
IDirect3DDevice9::CreatePixelShader: shaderapi’s centroid mask (0x00000000) differs from mask derived from shader name (0x0000000C) for shader ps-file flashlight_ps20b ps-index 0 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi’s centroid mask (0x00000000) differs from mask derived from shader name (0x0000000C) for shader ps-file flashlight_ps20b ps-index 0 ps-combo 1
IDirect3DDevice9::CreatePixelShader: shaderapi’s centroid mask (0x00000000) differs from mask derived from shader name (0x0000000C) for shader ps-file flashlight_ps20b ps-index 0 ps-combo 2
IDirect3DDevice9::CreatePixelShader: shaderapi’s centroid mask (0x00000000) differs from mask derived from shader name (0x0000000C) for shader ps-file flashlight_ps20b ps-index 0 ps-combo 3