Error with default value on predicate on 2.22.0

[Paolo Prete]

Hello,

I just experienced (on Linux) that this compiles with <= 2.20

--------------------------------

foo = #(define-music-function (parser location col staff mus)((color? red) string? ly:music?)
#{ c' d' #})

{
\foo "bar" {}
}

--------------------------------

But it doesn't compile with 2.22.0

What's wrong?

Thanks!