Add `scope.SetEnvironment`

Proposal: Allow setting Environment on the Scope

Unblocks

• https://github.com/getsentry/sentry-dotnet/issues/5387
• https://github.com/getsentry/sentry-unity/pull/2764

Summary

Add getEnvironment() / setEnvironment(String) to sentry-java's IScope, so other SDKs (hybrid SDKs like .NET, Godot, Unity, Unreal, React Native?) and end users can set the Environment on the scope at runtime. This lifts the restriction of having to provide it strictly at init via SentryOptions.setEnvironment(...).

This brings sentry-java to parity with sentry-cocoa and sentry-native. These already expose a scope-/runtime-level environment setter.

Motivation

Today environment in sentry-java lives only on SentryOptions, fixed at init time. Any hybrid SDKs layered on top either manage their own environment or provide a way for users to modify it at runtime. This creates the need to sync it into the Java layer at runtime. That way events, and persisted (background/ANR/NDK) events, carry the correct value.

Both reference SDKs already support this:

SDK	API	Level	Getter?
cocoa	- (void)setEnvironment:(NSString *)environment on Scope	scope	no
native	sentry_set_environment(const char *environment) (+ _n)	global scope	no
java	(proposed) IScope.setEnvironment(String) + getEnvironment()	scope	yes

Proposed API (sentry-java)

public interface IScope {
  // ...
  @Nullable String getEnvironment();

  /**
   * Sets the Scope's environment. Takes precedence over SentryOptions#getEnvironment()
   * when applied to events. Mainly used by hybrid SDKs to sync their environment.
   */
  void setEnvironment(@Nullable String environment);
}

Reached by users/hybrid SDKs the same way as other scope mutations:

Sentry.configureScope(scope -> scope.setEnvironment("staging"));

Unlike cocoa, we could also add a getter, consistent with other Java scope fields like getTransactionName, and getUser e.t.c. and required by the combined-scope view.

API References

sentry-cocoa

• SentryScope.h - (void)setEnvironment:(NSString *_Nullable)environment;
• SentryScope.m - sets environmentString, then notifies scope observers.
• SentryScope::applyToEvent - odering & backfill
• Usage: SentrySDK.configureScope { $0.setEnvironment("staging") }

sentry-native

• sentry.h - SENTRY_API void sentry_set_environment(const char *environment);
• sentry_core.c - overwrites scope->environment
• sentry__scope_apply_to_event
• Usage: sentry_set_environment("staging");

Precedence of application

Effective order from top to bottom: "environment set on the event itself" > scope > options**

• SentryClient.applyScope: applies scope environment to the event only when the event has none.
• MainEventProcessor.setEnvironment: later fallback to options.getEnvironment() when still unset

This matches the precedence used by cocoa and native.

Known gap / suggested follow-up

The Android AEI/ANR backfill processor reads environment only from the options cache, not the scope cache:

• ApplicationExitInfoEventProcessor.setEnvironment reads PersistingOptionsObserver.ENVIRONMENT_FILENAME, falling back to options.getEnvironment():

So a scope-set environment is persisted (via the new PersistingScopeObserver file) but is not picked up when backfilling exit-info events.
This could be resolved by reading the scope file first?