bin/shakapacker-config --doctor seems to create a number of additional config files, but it doesn't change the result of bin/shakapacker, nor do they seem to contain anything of substance:
That's because there is no configuration there, which is an erroneous state & evidence supporting my hypothesis. However, after testing my hypothesis, I discovered that the error wasn't caused by your code, but rather our library.
I apologize for that. Fortunately, while baseConfig is apparently broken, generateRspackConfig does work, although it may provide more configuration than you'd like. Please feel free to try my fork to confirm this. I've submitted a PR with the fix.
Originally posted by @Judahmeek in #827