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Hide bundled dependency symbols to prevent OpenTelemetry type clashes
The framework statically links OpenTelemetry (api/sdk), KSCrash, Kronos, SigmaSwiftStatistics and swift-code-coverage and exported all of their symbols. When a project-under-test links its own copy of the same dependency (e.g. opentelemetry-swift at a different version), dyld coalesces the duplicate weak type-metadata symbols to a single process-wide definition. Mismatched layouts then make one image read objects through the other's metadata, crashing in swift_getObjectType (observed via OpenTelemetryContextProvider.setActiveSpan). Mark every bundled-dependency symbol non-exported via UNEXPORTED_SYMBOLS_FILE so each image binds its own copy and dyld can't coalesce them. Only the public DatadogSDKTesting API stays exported (762 symbols vs ~11,240 before). Also drop DDInstrumentationControl.openTelemetryTracer and its README section: with OpenTelemetry now fully private, the documented `as? Tracer` interop can no longer work, so the hook is removed. Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
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‎DatadogSDKTesting-unexported-symbols.txt‎

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# Symbols to hide (make local / private_extern) in DatadogSDKTesting.framework.
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#
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# WHY: every dependency we statically link into the framework exports its
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# symbols by default. When a project-under-test links its OWN copy of the same
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# dependency (e.g. opentelemetry-swift), dyld coalesces the duplicate weak
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# type-metadata symbols to a single definition process-wide. If the two copies
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# differ in version/layout, one image ends up reading objects through the
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# other's metadata -> `swift_getObjectType` walks a bad pointer -> SEGV_ACCERR.
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# Marking these symbols non-exported stops dyld from coalescing them: each image
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# binds to its own copy. Only the public DatadogSDKTesting API stays exported.
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#
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# Passed to ld64 via `-unexported_symbols_list` (see UNEXPORTED_SYMBOLS_FILE /
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# OTHER_LDFLAGS on the framework target). Patterns use fnmatch globs and are
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# matched against the full mangled symbol name (leading underscore included).
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#
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# CAVEAT: this only prevents dyld symbol coalescing. It does NOT change the
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# mangled names, so name-keyed Swift runtime lookups (dynamic casts, Codable,
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# NSClassFromString) can still cross images in rare cases. For a hard guarantee
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# use module renaming instead. See the OpenTelemetry-isolation discussion.
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#
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# NOTE: Swift mangles the module name as a length-prefixed component
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# (e.g. `16OpenTelemetryApi`, 16 == strlen). It appears not only at the start of
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# symbols the module DEFINES but also mid-string in every symbol that REFERENCES
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# one of its types, so the globs are intentionally unanchored (`*...*`).
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# Keying on the length prefix keeps us from clobbering our own identifiers such
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# as `OpenTelemetryContextProvider` (mangled `28OpenTelemetry...`).
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# --- opentelemetry-swift-core ---
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*16OpenTelemetryApi*
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*16OpenTelemetrySdk*
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# --- swift-code-coverage ---
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*12CodeCoverage*
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*21CodeCoverageCollector*
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*18CodeCoverageParser*
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# --- Kronos ---
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*6Kronos*
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# --- SigmaSwiftStatistics ---
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*20SigmaSwiftStatistics*
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# --- EventsExporter (internal SDK module, not part of the public product) ---
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*14EventsExporter*
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# --- KSCrash (C/ObjC + Swift) ---
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# Modules: KSCrashRecording / RecordingCore / RecordingCoreSwift / ReportingCore
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# / Core / Filters / Sinks / Installations / DemangleFilter / etc.
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# NOTE: hiding C/ObjC symbols stops the linker-level duplicate, but the ObjC
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# runtime still registers classes by name and KSCrash installs process-wide
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# signal/exception handlers; if a project-under-test also links KSCrash that
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# handler-install conflict is a separate concern this list does NOT solve.
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# All KSCrash C functions are namespaced under `ks` (`_ksobjc_`, `_kscm_`,
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# `_ksjson_`, `_kscrash_`, ...); inline log wrappers are under `_i_ks`.
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*KSCrash*
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_ks*
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_i_ks*
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_OBJC_CLASS_$_KS*
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_OBJC_METACLASS_$_KS*

‎DatadogSDKTesting.xcodeproj/project.pbxproj‎

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SUPPORTS_MACCATALYST = YES;
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SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD = YES;
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SWIFT_EMIT_LOC_STRINGS = YES;
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UNEXPORTED_SYMBOLS_FILE = "$(SRCROOT)/DatadogSDKTesting-unexported-symbols.txt";
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};
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name = Debug;
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};
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SUPPORTS_MACCATALYST = YES;
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SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD = YES;
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SWIFT_EMIT_LOC_STRINGS = YES;
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UNEXPORTED_SYMBOLS_FILE = "$(SRCROOT)/DatadogSDKTesting-unexported-symbols.txt";
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};
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name = Release;
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};

‎README.md‎

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DDTest.current!.setTag(key: "key1", value: "value1")
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```
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## Using OpenTelemetry (only for Swift)
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The Datadog Swift testing framework uses [OpenTelemetry](https://github.com/open-telemetry/opentelemetry-swift) as the tracing technology under the hood. You can access the OpenTelemetry tracer using `DDInstrumentationControl.openTelemetryTracer` and can use any OpenTelemetry api. For example, for adding a tag/attribute:
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```swift
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import DatadogSDKTesting
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import OpenTelemetryApi
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let tracer = DDInstrumentationControl.openTelemetryTracer as? Tracer
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let span = tracer?.spanBuilder(spanName: "ChildSpan").startSpan()
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span?.setAttribute(key: "OTTag2", value: "OTValue2")
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span?.end()
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```
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The test target needs to link explicitly with `opentelemetry-swift`.
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## Using Info.plist for configuration
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Alternatively to setting environment variables, all configuration values can be provided by adding them to the `Info.plist` file of the Test bundle (not the App bundle). If the same setting is set both in an environment variable and in the `Info.plist` file, the environment variable takes precedence.

‎Sources/DatadogSDKTesting/DDInstrumentationControl.swift‎

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@objc public static func stopStderrCapture() {
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DDTestMonitor.instance?.stopStderrCapture()
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}
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public static var openTelemetryTracer: AnyObject? {
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return DDTestMonitor.instance?.tracer.tracerSdk
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}
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}

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