When your a0.dev app's iOS build fails on EAS, the cause is usually code signing, an invalid bundle identifier, or a config plugin problem — not the AI-generated code. Here is how to diagnose and fix the most common EAS iOS build failures.
Your a0.dev app previewed fine, but when you run an iOS production build on EAS, it fails. The logs are dense, and it is not obvious what went wrong.
The reassuring news is that iOS build failures are rarely caused by the AI-generated app logic. They almost always come from signing, identifiers, or native configuration.
Because a0.dev outputs a standard Expo project, these are the same failures any Expo iOS build can hit — which means they are well-documented and fixable.
This guide covers the most common causes in the order you should check them.
Code signing is a leading cause of iOS build failures. Every iOS binary must be signed with a valid distribution certificate and provisioning profile.
The simplest fix is to let EAS manage your credentials. When configured with your Apple credentials, EAS generates and stores the certificate and profile for you.
If you are managing credentials manually, verify that your distribution certificate is valid and not expired, and that your provisioning profile matches your bundle identifier.
Mismatches between the certificate, profile, and bundle identifier produce signing errors that halt the build. Aligning all three, or delegating to EAS, resolves most of them.
Your iOS bundle identifier must be a unique reverse-DNS string and must match across your app config, your Apple Developer account, and your provisioning profile.
If a0.dev left a placeholder identifier, or you changed it inconsistently, the build can fail because the identifier cannot be matched to valid credentials.
Set a proper bundle identifier like com.yourcompany.yourapp in your app config, and register it in your Apple Developer account if you manage credentials manually.
Consistency is everything here. The same identifier must appear everywhere, or Apple's signing chain breaks and the build stops.
If you added native modules, a config plugin error can break the prebuild step where EAS generates the native iOS project.
Check the logs for the phase that fails. Errors during native project generation usually point to a misconfigured or incompatible config plugin.
Make sure each native module's version matches your Expo SDK, and that any required config plugin is correctly added to your app config.
A module that is incompatible with your SDK version, or a plugin missing required options, will fail the build during prebuild rather than at runtime.
The iOS build reads your app config for essential values. Missing icons, an invalid version string, or malformed config can fail the build.
Verify your app has a valid name, version, build number, icon, and bundle identifier. Expo has specific requirements for asset sizes and formats.
A malformed app.json or app.config.js — a syntax error or an unexpected value — can break the build before it even reaches signing.
Validate your config carefully. Small mistakes here produce errors that look more serious than they are.
React Native and Expo projects are sensitive to dependency versions. A package that does not match your Expo SDK can fail the native build.
If you installed additional packages beyond what a0.dev generated, confirm they are compatible with your Expo SDK version.
Expo provides tooling to check for known incompatible dependency versions. Running that check often surfaces the exact package causing the failure.
Resolving to Expo-compatible versions, or removing an incompatible package, frequently clears a stubborn build failure.
If your app uses camera, location, notifications, or tracking, iOS expects matching permission declarations. Missing ones can cause build or later review problems.
Add the required usage description strings to your app config, typically via the relevant module's config plugin or the iOS infoPlist section.
While missing permission strings more often cause App Review rejection than a hard build failure, some misconfigurations do surface at build time.
Getting these right early avoids both a failed build and a later rejection, so treat them as part of your build checklist.
Read the EAS build logs from the bottom up and find the first real error, not just the final failure message. The first error usually names the actual cause.
If it mentions signing, certificates, or provisioning, fix credentials — ideally by letting EAS manage them — and confirm your bundle identifier is consistent everywhere.
If it fails during native project generation, suspect a config plugin or an incompatible native module, and check version alignment with your Expo SDK.
If it fails reading config, validate your app.json or app.config.js for missing values or syntax errors. Work one identified error at a time and rebuild.
Let EAS manage your iOS credentials whenever possible. This single choice eliminates the majority of signing-related build failures.
Set a real bundle identifier before your first build and keep it consistent across your config and Apple account. Never ship with a placeholder.
Keep dependencies aligned with your Expo SDK, and run Expo's compatibility check after installing new packages. Version drift is a silent build killer.
Finally, consult Expo's official build documentation when a failure is unclear. The logs plus the docs almost always pinpoint the cause, and both stay current with SDK changes.
When a build fails repeatedly, change one thing at a time between attempts. Fixing several things at once makes it impossible to know which change actually helped.
If the failure is hard to interpret, try a development or preview build profile as a comparison point. If that succeeds while production fails, the difference points you toward signing or distribution settings.
Clearing caches and rebuilding from a clean state can also eliminate failures caused by stale artifacts rather than real configuration errors.
The goal is a tight loop: make one targeted change, rebuild, read the first error, repeat. That rhythm resolves even stubborn failures faster than broad, speculative edits.
Occasionally a build fails for reasons outside your project — a transient infrastructure issue or a temporary service problem on the build platform.
You can usually recognize this because nothing in your project changed and the error does not reference your config, credentials, or dependencies.
In that case, simply retrying the build after a short wait often succeeds. Do not start rewriting your configuration in response to what may be a passing glitch.
If retries keep failing with the same non-project error, check the platform's status channels and documentation before assuming the problem is in your app.
Code signing and credentials. Every iOS binary needs a valid distribution certificate and provisioning profile that match the bundle identifier. Letting EAS manage credentials resolves most of these failures automatically.
Rarely. iOS build failures almost always come from signing, an invalid bundle identifier, config plugin issues, or dependency version conflicts — not from the app logic a0.dev generated.
Set a unique reverse-DNS identifier like com.yourcompany.yourapp in your app config, and ensure the same value appears in your Apple Developer account and provisioning profile. Inconsistency between them breaks Apple's signing chain.
This phase (prebuild) applies config plugins and native modules. A plugin missing required options, or a module incompatible with your Expo SDK version, fails here. Align module versions with your SDK and verify plugin configuration.
Read from the bottom up but find the first real error rather than the final summary message. That first error usually names the actual cause — signing, config, or a specific incompatible dependency — which tells you where to focus.