arranger.ly with lilypond 2.25 : intlog2 fatal error

[Raphael HARDY]

‌Hello!
I'm regularly using the arranger.ly library to make scores for children orchestras
When trying to use it with lilypond v2.25, I sometimes get
fatal error: intlog2 with negative argument: 0

For example using this small code that works as expected on 2.24 and triggers the fatal error on 2.25

\version "2.25.7"
%\version "2.24.2"
\include "arranger.ly"
\language "english"

global = { s1 * 4 } % get a 4 bars score

all = #'( flute ) % add instrument(s)

#(begin
  (init all)
  (fill 'flute #{ c''4 #} 1 5 ) ; fill 4 bars with quarter notes
  (rm 'flute '(3 -4) #{ r4 #} ) ; insert a rest one beat before bar 3
  )

\flute

%%%%%%

I can see where arranger.ly uses ly:intlog2 but I don't understand the error. Any idea on what could be the cause?