A build script phase failed (often the JS bundle step)

iOS / Xcode · last reviewed 2026-11-10

The error looks like this

Command PhaseScriptExecution failed with a nonzero exit code

Why it happens

Xcode cannot find node, or the Metro bundle step crashed. The real error is a few lines ABOVE this one.

How to fix it

Scroll up in the log for the first "error:" line.
Create ios/.xcode.env.local with: export NODE_BINARY=$(command -v node)
Test the bundle manually: npx react-native bundle --platform ios --dev false --entry-file index.js --bundle-output /tmp/main.jsbundle

Not sure this is your error? Let ReleaseMedic read the whole log

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