error during making GTest
googletest, linker-errors
Solution
Try moving `-lpthread` to after `gtest_main.a` in your g++ command.
Problem
I was trying to set up GTest environment on my Ubuntu machine. but while making the GTest to get the library, i get the following error... ``` som@som-VPCEH25EN:~/Workspace/CPP/gtest-1.6.0/make$ make g++ -I../include -g -Wall -Wextra -lpthread sample1.o sample1_unittest.o gtest_main.a -o sample1_unittest gtest_main.a(gtest-all.o): In function `~ThreadLocal': /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1336: undefined reference to `pthread_getspecific' /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1340: undefined reference to `pthread_key_delete' /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1336: undefined reference to `pthread_getspecific' /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1340: undefined reference to `pthread_key_delete' gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocator<testing::internal::TraceInfo> > >::GetOrCreateValue() const': /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1372: undefined reference to `pthread_getspecific' /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1379: undefined reference to `pthread_setspecific' gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::CreateKey()': /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1365: undefined reference to `pthread_key_create' gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocator<testing::internal::TraceInfo> > >::CreateKey()': /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1365: undefined reference to `pthread_key_create' gtest_main.a(gtest-all.o): In function `testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::GetOrCreateValue() const': /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1372: undefined reference to `pthread_getspecific' /home/som/Workspace/CPP/gtest-1.6.0/make/../include/gtest/internal/gtest-port.h:1379: undefined reference to `pthread_setspecific' collect2: ld returned 1 exit status make: *** [sample1_unittest] Error 1 ```