Description of problem: 
Trying to compile a c++ program with g++296 fail with undefined reference to pthread 
functions. 
 
Version-Release number of selected component (if applicable): 
compat-gcc-7.3-2.96.110 
compat-gcc-c++-7.3-2.96.110 
compat-libstdc++-7.3-2.96.110 
compat-libstdc++-devel-7.3-2.96.110 
 
How reproducible: 
Always. 
 
Steps to Reproduce: 
1. Create test.cpp which contains: 
#include <string> 
int main() 
{ 
    std::string s; 
    return 0; 
} 
2. Run: 
$ g++296 test.cpp 
     
Actual results: 
/tmp/ccdissG2.o(.__default_alloc_template<true, 
0>::_Lock::gnu.linkonce.t.(void)+0x12): In function `__default_alloc_template<true, 
0>::_Lock::_Lock(void)': 
: undefined reference to `pthread_mutex_lock' 
/tmp/ccdissG2.o(.gnu.linkonce.t._._Q2t24__default_alloc_template2b1i05_Lock+0x13): 
In function `__default_alloc_template<true, 0>::_Lock::~_Lock(void)': 
: undefined reference to `pthread_mutex_unlock' 
collect2: ld returned 1 exit status 
 
Expected results: 
Compiled file in a.out. 
 
Additional info: 
None.