feat(switch2): Nintendo Switch 2 support, and stop the offline transport raising system dialogs

[bitsandfoxes]

Brings up Nintendo Switch 2, and fixes three defects found while getting it working on a devkit. Each commit stands alone.

The reported problem

A Switch game that is offline showed the system "connect to the internet" dialog every couple of seconds, indefinitely.

UnityWebRequestTransport opens a connection per envelope, and on Switch the attempt itself is what raises the dialog. With logs and metrics both flushing on a 5s timer, that is a dialog every ~2.5s. A connection error only logged a warning and returned null, which also skipped the rate-limit handling in HttpTransportBase — so nothing anywhere recorded that the network was down, and the next envelope tried again immediately.

What's here

fix(switch): transport backoff — skip sending while the platform reports no network, and back off exponentially (1s→60s) after a connection error, resetting on the first success. Both paths record DiscardReason.NetworkError, so drops still show up in client reports instead of vanishing.

fix(switch): diagnostic logger no longer throws while logging — this one bit hard. With DisableFileWrite, resolving the installation ID falls through to NetworkInterface.GetAllNetworkInterfaces(), whose static initializer throws on Switch. Hub.ConfigureScope caught it and logged it — but stringifying that exception threw again, escaping the handler and aborting SDK init partway through registering integrations. Every Unity integration after GlobalRootScopeIntegration was left unregistered, so nothing was captured and no envelope was ever produced. A logger must never turn a handled error into a fatal one.

fix(switch2) + feat(switch2): Switch 2 support — UNITY_SWITCH2 selects SentryNativeSwitch, both asmdefs include the platform, and it gets its own plugin directory with no-op stubs. IsNativeSupportEnabled had no Switch2 case, so it fell through to the default and returned false — native support could never initialize regardless of configuration. Switch 2 shares SwitchNativeSupportEnabled and the existing Switch assembly, which is shipped to it via plugin metadata rather than by building a second assembly.

fix(switch): ask the platform for network availability — see below.

Why reachability isn't enough

Application.internetReachability reports a Switch console as reachable while it is offline. From the device:

Failed to send request: No Internet Connection.
Reachability reported as ReachableViaLocalAreaNetwork.

So the reachability gate was inert on the one platform it was written for, and the backoff absorbed everything — which reduced the dialogs to one per minute but could not remove them, because each retry is still an attempt.

sentry-switch now exposes sentry_switch_utils_is_network_available(), which asks the console's network interface manager without submitting a network request — so asking costs nothing and shows no dialog. SentryNativeSwitch supplies it as NetworkAvailabilityProbe and the transport prefers it, falling back to reachability when no probe is set, leaving WebGL and the unknown-platform path unchanged.

Verified on a Switch 2 devkit

Offline, with the probe in place:

Sentry: (Debug) Using the native SDK to determine network availability.
Sentry: (Debug) No network available. Dropping envelope instead of attempting to send.

No Failed to send request, no backoff, no dialogs — no UnityWebRequest is ever constructed, so nothing can raise one. Native init completes and scope sync is syncing breadcrumbs, user and trace.

Merge order

Depends on getsentry/sentry-switch#188, which must merge and ship first. The P/Invoke goes through __Internal against a statically linked archive, so it resolves at link time — a Switch player built against an older libsentry.a fails to link rather than falling back. The bundled stubs only cover the no-native-library case.

Not covered here

Two related issues left deliberately out of scope: SentryNativeBridge never sets network_connect_func, so the native transport does not start and native crash reports depend on Nintendo's upload path; and Hub's integration loop has no per-integration try/catch, which is why a single throwing Register could decapitate the SDK.

🤖 Generated with Claude Code

https://claude.ai/code/session_01ABHTqM37qGAc9iQZcdbdY8

[sentry]

Bug: An early return in SentryNativeSwitch.Configure prevents setting the NetworkAvailabilityProbe on Switch when native support is disabled, causing an unreliable network check.
_{Severity: MEDIUM}

Suggested Fix

Move the options.NetworkAvailabilityProbe = IsNetworkAvailable; assignment to before the if (!options.IsNativeSupportEnabled(platform)) check. This will ensure the reliable network probe is always configured for the Switch platform, regardless of the native support setting.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: src/Sentry.Unity.Native/SentryNativeSwitch.cs#L85-L90

Potential issue: In `SentryNativeSwitch.Configure`, an early `return` statement is
executed if `options.IsNativeSupportEnabled(platform)` is false. This prevents the
`options.NetworkAvailabilityProbe` from being set to the custom `IsNetworkAvailable`
function for the Nintendo Switch platform. Consequently, the transport layer falls back
to using `Application.internetReachability`, which is known to be unreliable on the
Switch and can incorrectly report the device as online. This defeats the purpose of a
fix designed to prevent offline error dialogs from appearing when the console is not
connected to the internet.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

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[bitsandfoxes]

Split into three focused PRs, since these are independent changes that happened to be found together:

• fix: stop the diagnostic logger from throwing while logging #2832 — UnityLogger no longer throws while logging
• fix(switch): stop offline sends raising the system connection dialog #2833 — offline sends no longer raise the system connection dialog
• feat(switch2): add Nintendo Switch 2 support #2834 — Nintendo Switch 2 support

Nothing is dropped; the combined branch is superseded by those three.