Fix build

cmake/Findnanomsg.cmake

@@ -0,0 +1,34 @@
+################################################################################
+# Copyright (C) 2014-2018 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH  #
+#                                                                              #
+#              This software is distributed under the terms of the             #
+#              GNU Lesser General Public Licence (LGPL) version 3,             #
+#                  copied verbatim in the file "LICENSE"                       #
+################################################################################
+
+find_path(NANOMSG_INCLUDE_DIR
+  NAMES nanomsg/nn.h
+  HINTS ${NANOMSG_ROOT} $ENV{NANOMSG_ROOT}
+  PATH_SUFFIXES include
+  DOC "Path to nanomsg include header files."
+)
+
+find_library(NANOMSG_LIBRARY_SHARED
+  NAMES libnanomsg.dylib libnanomsg.so
+  HINTS ${NANOMSG_ROOT} $ENV{NANOMSG_ROOT}
+  PATH_SUFFIXES lib
+  DOC "Path to libnanomsg.dylib libnanomsg.so."
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(nanomsg
+  REQUIRED_VARS NANOMSG_LIBRARY_SHARED NANOMSG_INCLUDE_DIR
+)
+
+if(NOT TARGET nanomsg AND nanomsg_FOUND)
+  add_library(nanomsg SHARED IMPORTED)
+  set_target_properties(nanomsg PROPERTIES
+    IMPORTED_LOCATION ${NANOMSG_LIBRARY_SHARED}
+    INTERFACE_INCLUDE_DIRECTORIES ${NANOMSG_INCLUDE_DIR}
+  )
+endif()