I am trying to add a file to a 3rd-party library we use at Tintri. I successfully edited Makefile.am. But the working Makefile.in and configure were generated with an older version of the auto-tools than what I have on my development machine. And, as is standard with the auto-tools, using the newer version doesn't work--- it generates a configure script with an error due to some missing macro--- and I can't be bothered to spend hours figuring out why.
So I instead copy/pasted all the relevant lines in Makefile.in with the new filename.
(Maybe I should have just added all the new code to an existing file.)