Undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'

Question

I just pulled a git repository in which me and my friends are developing an application. When I am running make I am facing this error:

undefined reference to symbol 'pthread_create@@GLIBC_2.2.5' /lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line collect2: error: ld returned 1 exit status Makefile:182: recipe for target 'bin/release/ns' failed make[1]: * [bin/release/ns] Error 1 Makefile:133: recipe for target 'release' failed make: * [release] Error 2

my friend pulled the same branch and he runs it without any problem.

Could you please give me some hints about the fix? Detailed answer would be highly appreciated.

[Add `-pthread` to your C++ compiler flags](http://stackoverflow.com/questions/2127797/gcc-significance-of-pthread-flag-when-compiling) (either manually or by [modifying `CXXFLAGS`](http://stackoverflow.com/questions/495598/difference-between-cppflags-and-cxxflags-in-gnu-make)). — набиячлэвэли, Dec 08 '15 at 20:37
Possible duplicate of [Strange linking error: DSO missing from command line](https://stackoverflow.com/questions/19901934/strange-linking-error-dso-missing-from-command-line) — perror, Jul 18 '17 at 16:45
Possible duplicate of [libpthread.so.0: error adding symbols: DSO missing from command line](https://stackoverflow.com/q/19901934/608639) and [Significance of -pthread flag when compiling](https://stackoverflow.com/questions/2127797/significance-of-pthread-flag-when-compiling) — jww, Mar 28 '19 at 14:10

score 57 · Accepted Answer · answered Apr 26 '20 at 10:50

57

I've been working on a multi-platform game engine and I faced same issue only on Linux. If you are using cmake add following to your cmake file:

SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")

If you are not using cmake you need to add this flag for your compiler manually.

The complete cmake for using threads in linux systems must contain following commands:

      set(CMAKE_THREAD_LIBS_INIT "-lpthread")
      SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")
      set(CMAKE_HAVE_THREADS_LIBRARY 1)
      set(CMAKE_USE_WIN32_THREADS_INIT 0)
      set(CMAKE_USE_PTHREADS_INIT 1)
      set(THREADS_PREFER_PTHREAD_FLAG ON)

Note: Also this fix works for Mac-Os but with one difference. You don't need to pass -pthread as compiler flag

answered Apr 26 '20 at 10:50

Mohammad f

961
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See [this answer](https://stackoverflow.com/a/29871891/635464) for a more complete approach with cmake. – mnme Nov 12 '20 at 10:56
2

I added `-pthread` to `LDFLAGS` in `Makefile` like `LDFLAGS = -lpq -lyaml -pthread` and `make` worked well. – esengineer Jan 22 '22 at 12:32
2

Thanks. This worked for me. SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread") – Nandini Chaurasiya Nov 18 '22 at 10:12

score 3 · Answer 2 · answered Mar 17 '18 at 09:19

3

You should add "-lpthread" to your library. Of cause, you should also add the directory of libpthread to your library directories.

answered Mar 17 '18 at 09:19

Y.Pengcheng

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3

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You should use -pthread for compile and link. It is *not* recommended to use -lpthread! From the manual: -pthread: Link with the POSIX threads library. This option is supported on GNU/Linux targets, most other Unix derivatives, and also on x86 Cygwin and MinGW targets. On some targets this option also sets flags for the preprocessor, so it should be used consistently for both compilation and linking. – Klaus Aug 08 '18 at 08:20
1

With modern Linux, using `-lpthread` alone results in something like `Undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'`. The `pthread` library is a special case and you should use compiler support for it and drop the lowercase L at the start: `-pthread`. – Mikko Rantalainen Jul 09 '22 at 15:37

Undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'

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