Undefined reference to pthread_create

[traversc]

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I got the following error when running ./build.sh

I'm on Ubuntu 20 with WSL. GCC 9.3.0

Another person posted the same issue earlier, but closed it: https://github.com/facebook/folly/issues/1377

How do I fix it?

Determining if the pthread_create exist failed with the following output:
Change Dir: /tmp/fbcode_builder_getdeps-ZhomeZtchingZDownloadsZfollyZbuildZfbcode_builder/build/folly/CMakeFiles/CMakeTmp

Run Build Command(s):/tmp/fbcode_builder_getdeps-ZhomeZtchingZDownloadsZfollyZbuildZfbcode_builder/installed/ninja-bbPkhaVDuJph3FgUpWo0w7J2R7ybohnLl2-cJn2LsPM/bin/ninja cmTC_0b481
[1/2] Building C object CMakeFiles/cmTC_0b481.dir/CheckSymbolExists.c.o
[2/2] Linking C executable cmTC_0b481
FAILED: cmTC_0b481
: && /usr/bin/cc   -rdynamic CMakeFiles/cmTC_0b481.dir/CheckSymbolExists.c.o  -o cmTC_0b481   && :
/usr/bin/ld: CMakeFiles/cmTC_0b481.dir/CheckSymbolExists.c.o: in function `main':
CheckSymbolExists.c:(.text+0x1f): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

File /tmp/fbcode_builder_getdeps-ZhomeZtchingZDownloadsZfollyZbuildZfbcode_builder/build/folly/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <pthread.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef pthread_create
  return ((int*)(&pthread_create))[argc];
#else
  (void)argc;
  return 0;
#endif
}

[rangelsfr]

My business account Global network

[ChristopherBignamini]

Hi, I'm not sure but it could be that a link to the pthread library (-lpthread) is missing at linking time. By adding "-v" to the compiler options it should be possible to check if that is the case.

[dimalit]

This affects me also. So what is the decision on how to change libfolly regarding this issue?

[lushengguo]

Focus on cmake error before this, which told me that Openssl is dependency and not found, after install openssl this pthread undefined problem resolved.

[hyperbolic-c]

Before error is can not find openssl so solution is sudo apt install libssl-dev