Compile fails on OSX ... can't find library rt

[walchko]

Looking at your CMakeLists.txt I don't think you want to add rt unless you are linux. I get the following error when it tries to build:

[kevin@tardis serial]$ make
cd build && cmake -DCMAKE_INSTALL_PREFIX=/tmp/usr/local ..
-- The C compiler identification is Clang 4.1.0
-- The CXX compiler identification is Clang 4.1.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Using CATKIN_DEVEL_PREFIX: /Users/kevin/tmp/serial/build/devel
-- Using CMAKE_PREFIX_PATH: /opt/ros/groovy
-- This workspace overlays: /opt/ros/groovy
-- Found PythonInterp: /usr/bin/python (found version "2.7.2") 
-- Found PY_em: /Library/Python/2.7/site-packages/em.pyc  
-- Found gtest: gtests will be built
-- catkin 0.5.52
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/kevin/tmp/serial/build
cd build && make
Scanning dependencies of target serial
[ 33%] Building CXX object CMakeFiles/serial.dir/src/serial.cc.o
[ 66%] Building CXX object CMakeFiles/serial.dir/src/impl/unix.cc.o
Linking CXX shared library devel/lib/libserial.dylib
ld: library not found for -lrt
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [devel/lib/libserial.dylib] Error 1
make[2]: *** [CMakeFiles/serial.dir/all] Error 2
make[1]: *** [all] Error 2
make: *** [serial] Error 2

You need to change CMakeLists.txt where you add library rt:

 if (UNIX AND NOT APPLE)
    target_link_libraries(${PROJECT_NAME} rt)
endif()

Here is the diff:

[kevin@tardis serial]$ git diff
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7ea1c80..216bc04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -37,7 +37,7 @@ endif()
 add_library(${PROJECT_NAME}
     ${serial_SRCS}
 )
-if (UNIX)
+if (UNIX AND NOT APPLE)
     target_link_libraries(${PROJECT_NAME} rt)
 endif()

[wjwwood]

Thanks, I actually had that before, but must have missed it in the move to catkin:

serial/serial.cmake

Line 79 in 5a2f127

if(UNIX AND NOT APPLE)

I'll get a fix for this asap.