Well that was fun, fathomed out how to run via NPM and it hung when starting react package manager, googled that and found this:
https://github.com/react-community/create-react-native-app/issues/234
So yeah, “sudo sysctl -w fs.inotify.max_user_watches=10000” fixed the issue, albeit until I reboot. To make it permanent it needs to be set in /etc/sysctl.d directory or /etc/sysctl.conf. Rather than rebooting to apply, “sudo sysctl -p --system” can apply it and then you just need to restart expo / terminal after.
Its also seems a common issue with intellij which is obviously doing alot with files / directory too Inotify Watches Limit - IntelliJ IDEA - Confluence, there’s a bit more info about what the problem is there / how inotify works.
Seems expo tries to either open this all in parallel / doesnt check the package manager actually starts, which suppresses the issue.
But yeah, now it works 