Support disabling Sentry for selected Unity platforms

[821869798]

Use case

We install Sentry Unity through OpenUPM and use it on desktop only. Android and iOS use Bugly, so Sentry is not initialized on those platforms.

Runtime guards prevent initialization, but the Sentry assemblies and dependencies can still be included in IL2CPP builds. In our comparison, enabling Sentry increased Managed/IL2CPP VM by about 15.9 MiB. We want to avoid this cost on platforms where Sentry is unused.

Request

Please provide an officially supported way to disable Sentry at compile time for selected Unity build targets, for example:

• a symbol such as SENTRY_UNITY_DISABLE; or
• a per-platform option in Sentry Project Settings.

When disabled, Sentry runtime code, native plugins, and managed dependencies should not be included in that player. The package should remain installed and updateable through OpenUPM so Sentry can still be used on desktop without maintaining a fork.

This is related to #2408, but specifically requests a per-platform compile-time opt-out.

[linear-code]

UNITY-231

[bitsandfoxes]

Hey, thanks for reaching out.!
And the issue is that you want to disable both, managed and native support?

To unblock yourself: You could do right now is to embed the package in your project and modify the SentryInitialization.cs to disable it there.

[821869798]

Yes, we want to disable both managed and native support for selected build targets.

Embedding the package and modifying SentryInitialization.cs can work as a temporary workaround, but it means maintaining local package changes and makes OpenUPM upgrades less convenient. Also, disabling initialization alone may not guarantee that the runtime assembly, aliased managed dependencies, and native plugins are fully excluded from the player.

What we are looking for is an officially supported per-platform compile-time opt-out that keeps the package installed for desktop while excluding all Sentry code and plugins from Android/iOS builds.

[bitsandfoxes]

I can see this being helpful not only in your specific case but to have a way of disabling the SDK without having to uninstall it. You will still need to wrap all your code calling into SentrySdk with a check for SENTRY_UNITY_DISABLE tho.