Removed some debug messages from the install phase, added some comments.

bash/link_file.cmake.in

-message("external process DESTDIR=$ENV{DESTDIR} INSTALL_PREFIX=@CMAKE_INSTALL_PREFIX@ SCRIPT_DIR=@COMPLETE_SCRIPT_DIR@")
+
+# This cmake script is used to provide relative links between the ligo_channel_completion
+# bash completion script and the names of the various commands that that get completed.
+# It is done in an external script as it needs to have access to the DESTDIR environment
+# variable (if present) which is found at run/install time, not at configuration time.
 
 # ideas from  https://stackoverflow.com/questions/35765106/symbolic-links-cmake
 set (LINK_ENTRIES "@COMPLETE_THESE_COMMANDS@")
@@ -6,6 +10,5 @@ foreach (entry ${LINK_ENTRIES})
     execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ligo_channel_completion ${entry}
         WORKING_DIRECTORY "$ENV{DESTDIR}@COMPLETE_SCRIPT_DIR@"
     )
-    message("-- Created symlink: for ${entry}")
+    message("-- Created symlink: for ${entry} in $ENV{DESTDIR}@COMPLETE_SCRIPT_DIR@")
 endforeach()
-message("Working dir = $ENV{DESTDIR}@COMPLETE_SCRIPT_DIR@")
\ No newline at end of file