makeinfo does not produce first output file when multiple files passed

[No Wayman]

makeinfo --version: texi2any (GNU texinfo) 7.1
Run on Arch Linux

Reproduction steps:

1. Clone the "emacs-eat" repository:

$ cd /tmp/
$ git clone https://codeberg.org/akib/emacs-eat.git

2. Within the repository, attempt to build 3 info files from the 3 
texi files in the repository:

$ cd ./emacs-eat
$ makeinfo fdl.texi -o fdl.info gpl.texi -o gpl.info eat.texi -o 
eat.info

This results in the last two info files being created (e.g. 
gpl.info and eat.info in this example).
The first file is not created regardless of the order they are 
passed.
Passing a "null" first argument results in all three files being 
generated:

$ makeinfo /dev/null fdl.texi -o fdl.info gpl.texi -o gpl.info 
eat.texi -o eat.info

Is this a misunderstanding on my part, or should all three files 
be generated with the first makeinfo command in the reproduction 
case?