Area and Iteration paths are not immediately available

In the code posted for a question of the same title (WorkItemMigrator module by Lars Wilhelmsen), the code appears to either

• creates area/iteration path structures, or
• migrate work items and relink

I tried creating area/iteration path structures, then immediate migrate work items and relink afterwards. The newly created area/iteration path structures seem not to be immediately available and the migration fail开发者_如何学Pythoned.

However, when I then run the code again, migration succeeded.

How can make the newly created area/iteration path structures immediately available, so migration and relinking can proceed successfully immediately afterwards?