concurrent builds fail due to shared use of /tmp/metro-cache/

Do you want to request a feature or report a bug?

bug

What is the current behavior?

Concurrently-running react-native builds often fail with e.g.:

ENOENT: no such file or directory, open '/tmp/metro-cache/03/2ed8513838f8bad0238a0a6032e415d1ea766f50f498e7d284ac6a05cb0b4000001234'

Error: ENOENT: no such file or directory, open '/tmp/metro-cache/03/2ed8513838f8bad0238a0a6032e415d1ea766f50f498e7d284ac6a05cb0b400001234'
    at Object.fs.openSync (fs.js:646:18)
    at Object.fs.writeFileSync (fs.js:1291:33)
    at FileStore.set (/Users/jenkins/src/node_modules/metro-cache/src/stores/FileStore.js:43:8)
    at Cache.set (/Users/jenkins/src/node_modules/metro-cache/src/Cache.js:96:31)
    at /Users/jenkins/src/node_modules/react-native/node_modules/metro/src/DeltaBundler/Transformer.js:127:13
    at Generator.next (<anonymous>)
    at step (/Users/jenkins/src/node_modules/react-native/node_modules/metro/src/DeltaBundler/Transformer.js:11:657)
    at /Users/jenkins/src/node_modules/react-native/node_modules/metro/src/DeltaBundler/Transformer.js:11:817
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)

If the current behavior is a bug, please provide the steps to reproduce and a minimal repository on GitHub that we can yarn install and yarn test.

What is the expected behavior?

I'd expect concurrently-running builds not to interfere with each other.

Please provide your exact Metro configuration and mention your Metro, node, yarn/npm version and operating system.

MacOS 10.13.3
node 8.9.4
npm 5.6.0
started seeing this when upgraded react-native from 0.55.4 to 0.57.2
=> (from our package-lock.json) metro went from 0.30.2 to 0.47.1

Start with metro-cache/src/stores/FileStore.js and follow the Cache.js and DeltaBundler/Transformer.js stack frames shown in the report. Reproduce concurrent React Native builds using the reported shared /tmp/metro-cache/ path and inspect how cache files and directories are handled. Done means concurrent builds no longer interfere with or remove each other’s cache entries.