12.11 Threading Libraries

The threading library must be linked to the binaries using a special linker flag -pthread on FreeBSD. If a port insists on linking -lpthread directly, patch it to use PTHREAD_LIBS variable provided by the ports framework. This variable usually has the value of -pthread, but on certain architectures and FreeBSD versions it can have different values, so do not just hardcode -pthread into patches and always use PTHREAD_LIBS.

Note: If building the port errors out with unrecognized option '-pthread' when setting PTHREAD_LIBS, it may be desirable to use cc as linker by setting CONFIGURE_ENV to LD=${CC}. The -pthread option is not supported by ld directly.

For questions about the FreeBSD ports system, e-mail <ports@FreeBSD.org>.
For questions about this documentation, e-mail <doc@FreeBSD.org>.