perf(native): load libcurl lazily in crash daemon

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Add `sentry_scope_remove_fingerprint` to remove a fingerprint set on a scope, matching the global `sentry_remove_fingerprint`. ([#1932](https://github.com/getsentry/sentry-native/pull/1932))
 - Add `sentry_options_set_before_send_feedback` to filter or enrich user feedback. Feedback does not go through `before_send`. ([#1923](https://github.com/getsentry/sentry-native/pull/1923))
 - Unix: Add `SENTRY_LINK_CURL` to control whether the curl transport links `libcurl` directly, loads it dynamically at runtime, or uses the default behavior. ([#1954](https://github.com/getsentry/sentry-native/pull/1954))
+- Native/Unix: The native crash daemon now loads `libcurl` dynamically at runtime by default when `SENTRY_LINK_CURL=AUTO`, avoiding `libcurl` linker work during process startup and significantly speeding up startup time. Explicitly set `SENTRY_LINK_CURL=ON` to link it directly. ([#1955](https://github.com/getsentry/sentry-native/pull/1955))
 
 **Fixes**:
 

CMakeLists.txt

@@ -875,7 +875,7 @@ elseif(SENTRY_BACKEND_NATIVE)
 	get_target_property(SENTRY_COMPILE_DEFS sentry COMPILE_DEFINITIONS)
 	if(SENTRY_COMPILE_DEFS)
 		# The daemon is always a static executable, never a shared library
-		list(REMOVE_ITEM SENTRY_COMPILE_DEFS "SENTRY_BUILD_SHARED")
+		list(REMOVE_ITEM SENTRY_COMPILE_DEFS "SENTRY_BUILD_SHARED" "SENTRY_LINK_CURL")
 		list(FILTER SENTRY_COMPILE_DEFS EXCLUDE REGEX "^SENTRY_INTEGRATION_")
 		target_compile_definitions(sentry-crash PRIVATE ${SENTRY_COMPILE_DEFS})
 	endif()
@@ -910,7 +910,11 @@ elseif(SENTRY_BACKEND_NATIVE)
 
 	# Transport-specific libraries
 	if(SENTRY_TRANSPORT_CURL)
-		sentry_target_link_curl(sentry-crash ${_SENTRY_LINK_CURL})
+		set(_SENTRY_CRASH_LINK_CURL ${_SENTRY_LINK_CURL})
+		if(SENTRY_LINK_CURL STREQUAL "AUTO" AND UNIX)
+			set(_SENTRY_CRASH_LINK_CURL OFF)
+		endif()
+		sentry_target_link_curl(sentry-crash ${_SENTRY_CRASH_LINK_CURL})
 	endif()
 
 	if(SENTRY_TRANSPORT_WINHTTP)

README.md

@@ -212,7 +212,8 @@ using `cmake -D BUILD_SHARED_LIBS=OFF ..`.
 - `SENTRY_LINK_CURL` (Default: `AUTO`):
   Controls whether the `curl` transport links `libcurl` directly or loads it
   dynamically at runtime on UNIX targets. Possible values are `AUTO`, `ON`, and
-  `OFF`. `AUTO` currently behaves like `ON`.
+  `OFF`. `AUTO` currently behaves like `ON`, except for the native crash daemon
+  on UNIX targets, where it behaves like `OFF`.
 
 - `SENTRY_BUILD_FORCE32` (Default: `OFF`):
   Forces cross-compilation from 64-bit host to 32-bit target. Only affects Linux.

src/backends/native/sentry_crash_daemon.c

@@ -4620,18 +4620,6 @@ sentry__crash_daemon_main(pid_t app_pid, uint64_t app_tid, HANDLE event_handle,
         }
     }
 
-    // Transport is already initialized by sentry_options_new(), just start it
-    if (options->transport) {
-        SENTRY_DEBUG("Starting transport");
-        sentry__transport_startup(options->transport, options);
-        // Set http_retry after transport startup to keep daemon-side retry
-        // polling disabled, while letting capture cache consent-revoked
-        // envelopes in retry format for the app to send on restart.
-        options->http_retry = ipc->shmem->http_retry;
-    } else {
-        SENTRY_WARN("No transport available");
-    }
-
     SENTRY_DEBUG("Daemon options fully initialized");
 
 #if defined(SENTRY_PLATFORM_LINUX) || defined(SENTRY_PLATFORM_ANDROID)
@@ -4661,6 +4649,18 @@ sentry__crash_daemon_main(pid_t app_pid, uint64_t app_tid, HANDLE event_handle,
     SENTRY_DEBUG("Signaling ready to parent");
     sentry__crash_ipc_signal_ready(ipc);
 
+    // Transport is already initialized by sentry_options_new(), just start it
+    if (options->transport) {
+        SENTRY_DEBUG("Starting transport");
+        sentry__transport_startup(options->transport, options);
+        // Set http_retry after transport startup to keep daemon-side retry
+        // polling disabled, while letting capture cache consent-revoked
+        // envelopes in retry format for the app to send on restart.
+        options->http_retry = ipc->shmem->http_retry;
+    } else {
+        SENTRY_WARN("No transport available");
+    }
+
     SENTRY_DEBUG("Entering main loop");
 
     // Daemon main loop