Hello, I stumble on another challenge during the software development of a small application which I derive from the Spirit tutorial on my openSUSE system. http://sourceforge.net/mailarchive/message.php?msg_id=31489573 I observe that a source file is accepted by my compilers in one build configuration. But error messages are displayed if I switch to the build configuration where the relevant source code is directly included by header files. Would you like to share any ideas on approaches to resolve this issue? https://github.com/elfring/boot_parameters/blob/d65ffb55c0643aac8cb02126066252e898b12bf9/boost/CMakeLists.txt Regards, Markus