[Compatibility BUG]. uutils tail breaks update-alternatives when run under pseudo

If you use pseudo to build a distribution (as Yocto/OpenEmbedded does) any attempt to run update-alternatives as part of packaging will fail.
The failure is caused by the uutils tail command.

This script, run on Kubuntu 25.10 with pseudo installed, shows the problem:

#!/bin/sh
# Assumes that pseudo is installed in /usr/bin
# and that libpseudo.so is in /usr/lib/x86_64-linux-gnu/pseudo/
#

# Set up the environment
#
rm -rf testenv testnew
mkdir -p testenv/bin testenv/var/pseudo
ln -s /usr/bin/pseudo testenv/bin/pseudo

# Set the environment variables to run pseudo
#
LD_PRELOAD=/usr/lib/x86_64-linux-gnu/pseudo/libpseudo.so
PSEUDO_PREFIX=`pwd`/testenv
export LD_PRELOAD PSEUDO_PREFIX

# Create a relevant update-alternatives file.
# (Without using uutyils cat, as thet produces:
#   couldn't allocate absolute path for 'null'.
# from pseudo....
#
(echo "/usr/bin/arch"
 echo "/bin/busybox.nosuid 50"
) > test-uaf

# This works, result is /bin/busybox.nosuid
#
echo "Running GNU tail"
result=`grep '50$' test-uaf | gnutail -n 1 | sed 's/ [^ ]*$//'`
echo "Result is: $result"
echo

# This fails, result is blank, and hence the resulting link is absent.
#
echo "Running uutils tail"
result=`grep '50$' test-uaf | tail -n 1 | sed 's/ [^ ]*$//'`
echo "Result is: $result"

The output from this is:

[gmllaptop]: ./test.sh 
Running GNU tail
Result is: /bin/busybox.nosuid

Running uutils tail
couldn't allocate absolute path for 'null'.
couldn't allocate absolute path for ''.
tail: cannot open 'standard input' for reading: No such file or directory
Result is: 

This might be related to https://github.com/uutils/coreutils/issues/9288

Start by running the shell reproducer from the issue with pseudo installed and compare uutils tail against GNU tail. Trace the tail invocation under LD_PRELOAD and PSEUDO_PREFIX, then verify that the uutils command produces the same selected line and no pseudo path errors.