Debootstrap could not install Debian Bullseye. How is it fixed?

I ran the latest debootstrap 1.0.126 (commit 9cd8a08 from http://salsa.debian.org/installer-team/debootstrap.git) but it threw Tried to extract package, but file already exists. Exit... error once it tried to unpack the first .deb file.

Searching for the error message in the source showed that it wants to unpack with dpkg-deb | tar x combination (functions:977). As it yet runs on the host system (not in chroot) I checked what my currently installed dpkg-deb version (1.16.18) says about a deb file (first one happened to be libacl1_2.2.53-10_i386.deb).

... contains not understood data member control.tar.xz, giving up

Well, it may give up, I don't. Fortunately, ar archiving tool understands the deb format too:

$ ar t libacl1_2.2.53-10_i386.deb
debian-binary
control.tar.xz
data.tar.xz

So I decided not to upgrade dpkg-deb, rather to replace the once-occuring dpkg-deb with ar:

# functions:977
ar p "$pkg" data.tar.xz | tar -v $EXTRACT_DEB_TAR_OPTIONS -xJf ...

Note the -J option added to tar. It failed when I did not specify the format explicitely, despite it indicated that XZ format was detected.