Error indicating that GLFW needs an OpenGL context to operate on, but none is currently set on the calling thread.
Ensure a context is current before calling functions that require a current context. This can be done with:
window = Espresso::Window.new(800, 600, "GLFW") window.current!
Espresso::Window.open(800, 600) do |window| # Code that uses the window here. end
#code : LibGLFW::ErrorCode
Underlying value that represents the error type.