cubicweb-pyramid #4669699 with cw 3.21, the default connection pool size is insufficient [open]

With 4, we get an instant cnx pool exhaustion.
With 5 things seem to work.

Without cubicweb_pyramid, the pb. does not show up.
Does it consume some cnx for itself ?

prioritynormal
typebug
done in<not specified>
closed by<not specified>