The issue is with the link the recipe is trying to fetch the files from. I suggest you to look for the right URL for the file the recipe needs. For example https://www.khronos.org/registry/khronos_headers.tgz which download the khronos_headers.tgz. You need to do some research into the angstrom layer you are using to see which specific file is needed. In the site https://www.khronos.org/registry/ are the list of files you can download and it seems from the URL that failed that it was trying to fetch OpenGL ES Headers, but the layer can give you more information on it. Usually when you get these fetch errors are due to broken links, firewall blocking the connection, proxy settings and other connection issues. I hope this helps.