Potty constructed to be flimsy (5-5)
I believe the answer is:
jerry-built
'flimsy' is the definition.
(thesaurus)
'potty constructed' is the wordplay.
'potty' becomes 'jerry' (I can't justify this - if you can you should believe this answer much more).
'constructed' becomes 'built' ('build' can be a synonym of 'construct').
'jerry'+'built'='JERRY-BUILT'
'to be' is the link.
Can you help me to learn more?
(Other definitions for jerry-built that I've seen before include "(Of housing) made from cheap materials" , "(Of houses) constructed to inferior standards" , "(Of house construction) flimsy" , "Bad or hastily constructed" .)