bug fix unbreak build on glibc >= 2.28

[Juraci]

Goal

@bugsnag/plugin-electron-client-state-persistence fails to compile on any system with glibc ≥ 2.28 (Ubuntu 18.10+, Debian 10+, Fedora 29+, Arch, etc.). The vendored tinycthread redefines once_flag and call_once against names that glibc now exposes through <stdlib.h>, producing conflicting types for 'pthread_once_t' and conflicting types for 'pthread_once' errors during node-gyp rebuild. This breaks npm install for any consumer of @bugsnag/electron on a current Linux distro that doesn't have a prebuilt binding cached.

Design

The plugin uses only mtx_t, mtx_init, mtx_lock, mtx_unlock, and mtx_plain from tinycthread (see src/bugsnag_electron_client_state_persistence.c). once_flag, ONCE_FLAG_INIT, and call_once are never referenced on POSIX — the only call_once definition in tinycthread.c is gated behind #if defined(_TTHREAD_WIN32_).

Since the colliding code is dead on POSIX, the smallest and safest fix is to drop the POSIX #else branches entirely. The Win32 typedef struct once_flag and void call_once(...) declarations are untouched, preserving Windows behaviour.

A more durable fix would be to drop the vendored tinycthread on platforms that ship C11 <threads.h> and use the system header. That's a larger change; happy to do it as a follow-up if reviewers prefer.

Changeset

packages/plugin-electron-client-state-persistence/src/deps/tinycthread/tinycthread.h: deletes the two POSIX #else branches (5 lines total) that redefine once_flag / ONCE_FLAG_INIT / call_once. No other files modified.

@@ -456,9 +456,6 @@ int tss_set(tss_t key, void *val);
     CRITICAL_SECTION lock;
   } once_flag;
   #define ONCE_FLAG_INIT {0,}
-#else
-  #define once_flag pthread_once_t
-  #define ONCE_FLAG_INIT PTHREAD_ONCE_INIT
 #endif

 /** Invoke a callback exactly once
@@ -468,8 +465,6 @@ int tss_set(tss_t key, void *val);
  */
 #if defined(_TTHREAD_WIN32_)
   void call_once(once_flag *flag, void (*func)(void));
-#else
-  #define call_once(flag,func) pthread_once(flag,func)
 #endif

Testing

Manual:

• npm install && npx node-gyp rebuild in packages/plugin-electron-client-state-persistence succeeds on Arch Linux (glibc 2.43); produces build/Release/bugsnag_pecsp_bindings.node. Without this patch, the same command fails with conflicting types for 'pthread_once_t'.
• CI to confirm Linux / macOS / Windows builds remain green (Win32 branch is untouched; POSIX-side macros were dead code, so no behavioural change is expected).

Automated:

• No new tests added — the change deletes dead-code macro definitions on POSIX. Existing CI build steps for the plugin exercise the regression surface.

Platform	Before	After
Linux glibc ≥ 2.28	build fails	builds
Linux glibc < 2.28	builds	builds (macros removed but unused)
macOS	builds	builds (macros removed but unused)
Windows	builds	builds (Win32 branch untouched)

[Copilot]

Pull request overview

This PR fixes a Linux build regression in the native @bugsnag/plugin-electron-client-state-persistence addon by removing POSIX once_flag/call_once shims from the vendored tinycthread header, avoiding symbol collisions with newer glibc headers. I verified the package’s native code only uses mtx_* from tinycthread, so the removed POSIX once-only API is not used by this addon.

Changes:

• Removes the POSIX once_flag/ONCE_FLAG_INIT aliases from vendored tinycthread.h.
• Removes the POSIX call_once alias while leaving the Win32 declaration/implementation path intact.
• Keeps the Electron client-state persistence package buildable on current Linux distributions without changing the addon’s runtime behavior.

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[hannah-smartbear]

Hi @Juraci,

Thanks for raising this PR. Our engineers will take a look, and any comments or updates will be posted here accordingly.