When linking against libtt (a C++ lib) the link stage should use the C++

linker

cde/programs/dtcalc/Imakefile

@@ -31,6 +31,12 @@ SYS_LIBRARIES = -lm -lgen
 #if defined(HPOSFArchitecture)
 #endif
 
+XCOMM On Linux once you link against a C++ library the whole program 
+XCOMM has to be linked with the C++ linker
+#if defined(LinuxDistribution)
+CCLINK = $(CXX)
+#endif
+
 SRCS =  calctool.c      ds_common.c     ds_popup.c \
         ds_widget.c     ds_xlib.c       functions.c \
         help.c          motif.c         mp.c \