1) "Unable to load OpenGL". I compile it myself, then it works right away.
2)
GLSL error LX_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_create_context_es2_profile GLX_EXT_create_context_es_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
The rectangle that should appear does not come. I change Load_GL_VERSION_3_3_CORE () to Load_GL_VERSION_3_2_CORE () then it runs. Also, the expected text appears in the caption.
Whatever is funny, I deliberately make a Systax error in the shader code, then not even throwing a mistake.
By the way, I have already broken my head because of the Core, but unfortunately I have not come further, unfortunately you can see that in my tutorial, in context generation.
For this reason, I have outsourced the whole thing in a unit, but if I can manage it, I can only change the unit, instead of the whole tutorial.
I also asked questions in the Maillist of FPC, there was no advice.