New CI=true build configuration, "Treating warnings as errors because process.env.CI = true"

This broke my app. I then went and did the recommended fix and set the build command to CI= npm run build in settings. That solved my problem and I was able to deploy my app again.

Now, a couple days later, I’m getting an error again:

┌─────────────────────────────┐
8:16:52 PM: │ “build.command” failed │
8:16:52 PM: └─────────────────────────────┘
8:16:52 PM: ​
8:16:52 PM: Error message
8:16:52 PM: Command failed with exit code 1: CI= npm run build
8:16:52 PM: ​
8:16:52 PM: Error location
8:16:52 PM: In Build command from settings:
8:16:52 PM: CI= npm run build
8:16:52 PM: ​
8:16:52 PM: Resolved config
8:16:52 PM: build:
8:16:52 PM: command: CI= npm run build
8:16:52 PM: publish: /opt/build/repo/build

How do I fix this? CI= npm run build is still set in the settings but now I’m getting another error after this previously worked.