opensysusers' usage function describes `--replaces` as this:

+---
| --replace=PATH Don't run check in the package
+---[ opensysusers ]

It is only used in a conditional:

+---
| if [ "$#" -eq 0 ] || [ -n "${replace}" ]; then
+---

I have no idea what the description wants to say and the
implementation doesn't seem related to it. Both ways also don't match
systemd-sysusers behavior as described in man:systemd-sysusers(8):

+---
| --replace=PATH
|
| When this option is given, one or more positional arguments must be
| specified. All configuration files found in the directories listed
| in sysusers.d(5) will be read, and the configuration given on the
| command line will be handled instead of and with the same priority
| as the configuration file PATH.
+---[ man:systemd-sysusers(8) ]

Ansgar

We believe that the bug you reported is fixed in the latest version of
opensysusers, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1055777@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Andrea Pappacoda <andrea@pappacoda.it> (supplier of updated opensysusers package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Mon, 16 Sep 2024 01:05:24 +0200
Source: opensysusers
Architecture: source
Version: 0.7.3-3
Distribution: unstable
Urgency: medium
Maintainer: Andrea Pappacoda <andrea@pappacoda.it>
Changed-By: Andrea Pappacoda <andrea@pappacoda.it>
Closes: 1055777
Changes:
 opensysusers (0.7.3-3) unstable; urgency=medium
 .
   * First dgit upload
   * d/control: apply X-Style: black
   * d/control: add missing depends on passwd
   * d/tests: add simple autopkgtest
   * d/tests: add --root test
   * d/patches: fix --root option (Closes: #1055777)
Checksums-Sha1:
 2a1530aa32109e9d94438e0ff39e160811a9d8ac 1472 opensysusers_0.7.3-3.dsc
 148a3909713868d145330ad716b62c4076b2145f 5664 opensysusers_0.7.3-3.debian.tar.xz
Checksums-Sha256:
 8ea6c0f40dbba598119413174b17fa61611682196016d3d9717fc5b45e8c7cf7 1472 opensysusers_0.7.3-3.dsc
 ac6a9ba70f87eab3c0e95fc6c886a586c66b035ec966d6e4b689020e59ff2f91 5664 opensysusers_0.7.3-3.debian.tar.xz
Files:
 7567e506148c1d47b67cd06d44d7b124 1472 admin optional opensysusers_0.7.3-3.dsc
 64604d44d673ada07c4fb799314814eb 5664 admin optional opensysusers_0.7.3-3.debian.tar.xz
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Ops, version 0.7.3-3 closed bug #1055517, not #1055777. Guess you
shouldn't try fixing critical bugs at 1 am...