why pg_restore ignores --create ? Error: failed: FATAL: database "new_db" does not exist
This is because it is the way pg_restore works.

pg_restore manual reads as follow :


  -C, --create
             Create the database before restoring into it. If --clean is also specified, drop and recreate the target database before
  connecting to it.
  
  When this option is used, the database named with -d is used only to issue the initial DROP DATABASE and CREATE DATABASE
  commands. All data is restored into the database name that appears in the archive.


The -d will restore in the given database if and only if -C is not used. If -C is used, the database is used as a "launchpad", not as the destination.