It was around 12:30a, and I got a wonderful error message when attempting to pin the version of my recent push to the other repository that depends on that code:
I went to bed, but the error was still there for me in the morning. Saving you my fruitless Googling process, I finally solved the issue by reading the error message (ha) and realizing that something was deeply wrong with the Go cache on my local system (I had thought something was wrong with my .git file). I fixed this by running:
go clean -cache -modcache -i -r
This fixed it for me! Be warned that you will have to reinistall all of your go dependencies again (go get ./...), but other than that, my life is back to sweet, sweet ignorance about what the Go cache is doing behind the scenes.
Happy coding!