Eu estava tentando configurar o ambiente GTest na minha máquina Ubuntu. mas ao fazer o GTest para obter a biblioteca, recebo o seguinte erro ...

<code>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
</code>