[CMake] set RPATH for plugins

the install rpath allow plugins to find each other

ROS buildfarm test everything in isolated environments, se we must also
set the build rpath

Author: nim65s

src/CMakeLists.txt

@@ -1,5 +1,8 @@
 # Copyright 2010, 2020, François Bleibel, Olivier Stasse, Guilhem Saurel, JRL, CNRS/AIST, LAAS-CNRS
 
+# ROS buildfarm uses isolated environments, in which the build rpath is used
+set(BUILD_WITH_INSTALL_RPATH TRUE)
+
 SET(plugins
   sot/sot
 
@@ -91,6 +94,7 @@ set(task-unilateral_deps task)
 FOREACH(plugin ${plugins})
   GET_FILENAME_COMPONENT(LIBRARY_NAME ${plugin} NAME)
   ADD_LIBRARY(${LIBRARY_NAME} SHARED ${plugin})
+  SET_TARGET_PROPERTIES(${LIBRARY_NAME} PROPERTIES INSTALL_RPATH $ORIGIN)
 
   IF(SUFFIX_SO_VERSION)
     SET_TARGET_PROPERTIES(${LIBRARY_NAME} PROPERTIES SOVERSION ${PROJECT_VERSION})