Другой вариант поиска

FindIonobase.cmake

@@ -12,7 +12,8 @@ if(NOT IONOBASE_IS_EXTERNAL_PROJECT)
   endif()
   find_path(
     IONOBASE_INCLUDE_DIRS
-    NAMES ionobase/interchfor.h
+    NAMES interchfor.h
+    PATH_SUFFIXES ionobase
     PATHS ${_search_paths})
 
   set(_search_paths "")

FindIonobaseThirdparty.cmake

@@ -27,10 +27,10 @@ set(IONOBASE_PREFIX
     ${CMAKE_BINARY_DIR}
     CACHE FILEPATH "" FORCE)
 set(IONOBASE_INCLUDE_DIR
-    ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_INCLUDEDIR}
+    ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_INCLUDEDIR}/ionobase
     CACHE PATH "" FORCE)
 set(IONOBASE_INCLUDE_DIRS
-    ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_INCLUDEDIR}
+    ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_INCLUDEDIR}/ionobase
     CACHE PATH "" FORCE)
 set(IONOBASE_LIBRARY_DIR
     ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}

FindSignalView.cmake

@@ -4,7 +4,7 @@ if(NOT SIGNALVIEW_IS_EXTERNAL_PROJECT)
   set(SIGNALVIEW_LIBRARY_DIR "" CACHE PATH "The path to the library of an libsignalview installation")
 
   set(_search_paths "")
-  if(SIGNALVIEW_INLCUDE_DIR AND EXISTS ${SIGNALVIEW_INCLUDE_DIR})
+  if(SIGNALVIEW_INCLUDE_DIR AND EXISTS ${SIGNALVIEW_INCLUDE_DIR})
     list(APPEND _search_paths ${SIGNALVIEW_INCLUDE_DIR})
   endif()
   if(SIGNALVIEW_PREFIX AND EXISTS ${SIGNALVIEW_PREFIX})