In package.json engines field, node version is defined as 12.14.1. https://docs.npmjs.com/files/package.json#engines
But Netlify build process ignores this information and uses default node version 10.18.1 instead, which causes build error like this:
11:13:49 PM: Finished restoring cached yarn cache
11:13:50 PM: Installing NPM modules using Yarn version 1.17.0
11:13:51 PM: yarn install v1.17.0
11:13:51 PM: [1/5] Validating package.json…
11:13:51 PM: error firstname.lastname@example.org: The engine “node” is incompatible with this module. Expected version “12.14.1”. Got “10.18.1”
11:13:51 PM: error Found incompatible module.
11:13:51 PM: info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
11:13:51 PM: Error during Yarn install
11:13:51 PM: Error running command: Build script returned non-zero exit code: 1
11:13:51 PM: failed during stage ‘building site’: Build script returned non-zero exit code: 1
11:13:51 PM: Failing build: Failed to build site
11:13:51 PM: Finished processing build request in 18.084510139s
Please check engines.node and apply correct version before building application. Thanks.