Andreas Schwab wrote: > It is likely that the use of weak pthread symbols is not confined to > gnulib.
Yes. Between 2000 and 2010 I heard a couple of times "Multithreading support is only available through libpthread. It is a common technique to use weak symbols to distinguish a program linked with -lpthread from a program not linked with -lpthread (and such a program is single-threaded)". Also, people were saying "dlopen of libpthread does not work" [1][2]. Bruno [1] https://jmmv.dev/2004/11/dynamic-open-of-libpthread-considered.html [2] https://sourceware.org/bugzilla/show_bug.cgi?id=18192
