Fork error on tvOS and watchOS

[paulocoutinhox]

Hi,

When i try build version 1.10.1 for tvOS i get this error:

In file included from /Users/paulo/.conan/data/poco/1.10.1/_/_/build/38267c8c71293c0f1dfff4a217e3a33b60e9b7fd/source_subfolder/Foundation/src/Process.cpp:59:
/Users/paulo/.conan/data/poco/1.10.1/_/_/build/38267c8c71293c0f1dfff4a217e3a33b60e9b7fd/source_subfolder/Foundation/src/Process_UNIX.cpp:190:12: error: 'fork' is unavailable: not available on tvOS
        int pid = fork();
                  ^
/Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS14.5.sdk/usr/include/unistd.h:447:8: note: 'fork' has been explicitly marked unavailable here
pid_t    fork(void) __WATCHOS_PROHIBITED __TVOS_PROHIBITED;
         ^
In file included from /Users/paulo/.conan/data/poco/1.10.1/_/_/build/38267c8c71293c0f1dfff4a217e3a33b60e9b7fd/source_subfolder/Foundation/src/Process.cpp:59:
/Users/paulo/.conan/data/poco/1.10.1/_/_/build/38267c8c71293c0f1dfff4a217e3a33b60e9b7fd/source_subfolder/Foundation/src/Process_UNIX.cpp:231:3: error: 'execvp' is unavailable: not available on tvOS
                execvp(argv[0], &argv[0]);
                ^
/Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS14.5.sdk/usr/include/unistd.h:446:6: note: 'execvp' has been explicitly marked unavailable here
int      execvp(const char * __file, char * const * __argv) __WATCHOS_PROHIBITED __TVOS_PROHIBITED;
      

I see that is in this line:
https://github.com/pocoproject/poco/blob/poco-1.10.1/Foundation/src/Process_UNIX.cpp#L190

And a define is checked is this line:
https://github.com/pocoproject/poco/blob/poco-1.10.1/Foundation/src/Process_UNIX.cpp#L175

I need add in conan a variable to pass this directive, correct?

Thanks.

[obiltschnig]

Assuming this is built via CMake, then the -DPOCO_NO_FORK_EXEC must be added to the compiler options when compiling Foundation for watchOS/tvOS. Since there does not seem to be a standard way of detecting watchOS/tvOS builds in CMake, this should probably be handled via an extra configuration variable passed to the build externally.

[obiltschnig]

See #3347