[crashpad] Add compilation condition restrictions to fix sentry-native linux runtime error

[JonLiu1993]

When install sentry-native:x64-linux in vcpkg, the cmake project generation & building it works fine, however while trying to run the app with dummy crash (assigning a nullptr after initialization of sentry) the crash raport doesn't gets send to the sentry backend.

[1717:1717:20240604,064748.491454:FATAL pthread_create_linux.cc:54] Check failed: next_pthread_create. dlsym: RTLD_NEXT used in code not dynamically loaded

Add constraint to compile pthread_create_linux.cc only when BUILD_SHARED_LIBS to fix error。
Related issue:getsentry/sentry-native#596
microsoft/vcpkg#39114

[supervacuus]

Hi @JonLiu1993, I'm sorry, but I cannot reproduce this. Would you happen to have a non-vcpkg-based CMake configuration to repro this so I can test it? I don't see the described issue when running static builds on Linux.

Also, from the linked issues, I cannot understand why BUILD_SHARED_LIBS should be the discriminator since it affects add_library() only, but this involves an executable (the crashpad_handler).

The Native SDK issue getsentry/sentry-native#596 highlights the offending source but does not mention how that could relate to building sentry as a static artifact.

Could the issue be related to using static standard libraries rather than static sentry builds? If so, I would prefer to find a better condition for that scenario because the pthread_create-wrapper could still make sense in the crashpad_handler if sentry is built as a static library on Linux.

[JonLiu1993]

@supervacuus, Thank you for your reply. Actually, this problem is encountered by vcpkg users. Since I don't have the conditions to reproduce it, I followed the upstream related issue getsentry/sentry-native#596 to fix it and it can be used by user testing. So I submitted or issue. You can ask @Patrix9999 for the specific steps to reproduce it.