yarn install vs yarn upgrade (install not working)

I have react app based on create-react-app. This is what I do:

• remove the node_modules directory
• yarn install --pure-lockfile
• yarn build

Then this results in an error: npm ERR! Linux 4.4.0-78-generic npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "run" "build-js" npm ERR! node v6.10.3 npm ERR! npm v3.10.10 npm ERR! code ELIFECYCLE npm ERR! project@0.1.0 build-js: `react-scripts build` npm ERR! Exit status 1

But when I do this:

• remove the node_modules directory
• yarn upgrade
• yarn build

Everything works fine. And note that there is nothing updated, the yarn.lock file stays the same.

Can anybody explain this difference?

via zjeraar