Is this a stupid question?

Was I supposed to clone the GitHub repository before trying to build the image?

I ask because I've just seen these errors

 => ERROR [2/4] COPY patches/ /tmp/patches/                                0.0s
 => CACHED [3/4] RUN   echo "**** install build packages ****" &&   apk a  0.0s
 => ERROR [4/4] COPY root/ /                                               0.0s
------
 > [2/4] COPY patches/ /tmp/patches/:
------
------
 > [4/4] COPY root/ /:
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Dockerfile:63
--------------------
  61 |     
  62 |     # add local files
  63 | >>> COPY root/ /
  64 |     
  65 |     # ports and volumes
--------------------
ERROR: failed to solve: failed to compute cache key: failed to calculate checksum of ref 2ad57b92-028a-429f-a2de-be0e9a7f57af::cz3t2511b10hmumww1m73cse6: "/root": not found

And being as n00b as I am, I'm instantly trying to attribute the blame to me not doing something.