TAOCP itself embodies several layers of yak shaving, since he was initially commissioned to write a book on compilers, then decided to start the book with mater

TAOCP itself embodies several layers of yak shaving, since he was initially commissioned to write a book on compilers, then decided to start the book with material on more basic algorithms (with compilers relegated to later chapters), then each pair of chapters expanded to become its own volume, then volume 4 expanded to become three or more volumes. 60 years later he still hasn't gotten to the compiler part yet! (which is supposed to be volume 7)