Wrap(ErrInsufficientFunds, "40 < 500") returns strings like
"insufficient funds: 40 < 50". Although he function syntax
fits perfectly SDK app developers use case and as such it
should not be changed, the interface is still counter-intuitive
as most Golang developers may reasonably expect a different
result similar to what other popular libraries' (see [1])
would produce (e.g. "40 < 500: insufficient funds").
Follow up PR of #5876.
[1] https://godoc.org/github.com/pkg/errors#Wrapf
Alessio Treglia
0ba4e3a630