it would have been necessary
En tout cas, pas comme il aurait fallu.
In any case, not as it should have been.
— The Little Thief (1988)
Il aurait fallu avoir un scénario.
There should have been a script.
— Mysterious Object at Noon (2000)
Il aurait fallu prévenir avant, pas après.
They should have warned us beforehand, not after.
Mais avec qui il aurait fallu que je couche pour avoir une job comme ça ?
But who would I have had to sleep with to get a job like that?
— Les Invasions barbares (2003)
Il aurait fallu que je te remarque, mais oui.
I should have noticed you, but yes.
— Douleur et gloire (2019)
Il aurait fallu que vous ayez un vaisseau suffisamment protégé.
You should have had a sufficiently well-protected vessel.
— Star Trek: The Next Generation - All Good Things... (2014)