compile problem — undefined reference to `pthread_xxxx'

Building Synergy on Ubuntu 13.10 gets the error below.

When I manually change /usr/local/src/synergy-1.4.15-Source/src/cmd/synergyd/CMakeFiles/synergyd.dir/link.txt to put libraries that have the -lpthread option at the end of the line then it builds properly.

How can this be changed so that other people don't face the same issue?

initial build error output

../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::newMutex()':
CArchMultithreadPosix.cpp:(.text+0x319): undefined reference to `pthread_mutexattr_init'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::raiseSignal(IArchMultithread::ESignal)':
CArchMultithreadPosix.cpp:(.text+0x43b): undefined reference to `pthread_kill'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::threadSignalHandler(void*)':
CArchMultithreadPosix.cpp:(.text+0x490): undefined reference to `pthread_detach'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::closeThread(CArchThreadImpl*)':
CArchMultithreadPosix.cpp:(.text+0x62b): undefined reference to `pthread_detach'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::newThread(void* (*)(void*), void*)':
CArchMultithreadPosix.cpp:(.text+0x8e6): undefined reference to `pthread_sigmask'
CArchMultithreadPosix.cpp:(.text+0x90f): undefined reference to `pthread_sigmask'
CArchMultithreadPosix.cpp:(.text+0x935): undefined reference to `pthread_create'
CArchMultithreadPosix.cpp:(.text+0x9a4): undefined reference to `pthread_create'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::CArchMultithreadPosix()':
CArchMultithreadPosix.cpp:(.text+0xe11): undefined reference to `pthread_mutexattr_init'
CArchMultithreadPosix.cpp:(.text+0xf05): undefined reference to `pthread_sigmask'
CArchMultithreadPosix.cpp:(.text+0xf26): undefined reference to `pthread_sigmask'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::startSignalHandler()':
CArchMultithreadPosix.cpp:(.text+0x10a8): undefined reference to `pthread_sigmask'
CArchMultithreadPosix.cpp:(.text+0x10cd): undefined reference to `pthread_sigmask'
CArchMultithreadPosix.cpp:(.text+0x1104): undefined reference to `pthread_create'
../../../../../lib/libarch.a(CArchMultithreadPosix.o): In function `CArchMultithreadPosix::cancelThread(CArchThreadImpl*)':
CArchMultithreadPosix.cpp:(.text+0x5e3): undefined reference to `pthread_kill'
collect2: error: ld returned 1 exit status
make[2]: *** [../../bin/synergyd] Error 1
make[1]: *** [src/cmd/synergyd/CMakeFiles/synergyd.dir/all] Error 2
make: *** [all] Error 2
Going back to: /usr/local/src/synergy-1.4.15-Source
Error: make failed: 512

fixed synergy-1.4.15-Source/src/cmd/synergyd/CMakeFiles/synergyd.dir/link.txt

/usr/bin/c++   -O3 -DNDEBUG    CMakeFiles/synergyd.dir/synergyd.o  -o ../../../bin/synergyd -rdynamic ../../../lib/libarch.a ../../../lib/libbase.a ../../../lib/libcommon.a ../../../lib/libio.a ../../../lib/libipc.a ../../../lib/libmt.a ../../../lib/libnet.a ../../../lib/libplatform.a ../../../lib/libsynergy.a ../../../lib/libclient.a ../../../lib/libserver.a ../../../lib/libipc.a ../../../lib/libplatform.a ../../../lib/libsynergy.a ../../../lib/libclient.a ../../../lib/libarch.a ../../../lib/libbase.a ../../../lib/libcommon.a ../../../lib/libnet.a ../../../lib/libmt.a ../../../lib/libio.a ../../../lib/libcryptopp.a ../../../lib/libcryptopp.a -lpthread -lSM -lICE -lXtst -lX11 -lXext -lXinerama -lXrandr -lXi ../../../lib/libserver.a -lpthread -lSM -lICE -lXtst -lX11 -lXext -lXinerama -lXrandr -lXi