A little demonstration of how symlinked directories can cause surprising behavior

symlinks-are-weird.sh

#!/bin/bash

# Make a little tmpdir (and delete it when we're done)
tmpdir=$(mktemp -d) && [ -d $tmpdir ] && trap "rm -rf $tmpdir" EXIT
tree1=$tmpdir/tree1
tree2=$tmpdir/tree2

# Make an example tree
mkdir -p $tree1/etc/pki/rpm-gpg
mkdir -p $tree1/etc/pki/ca-trust
echo "TREE1" > $tree1/etc/tree-id

# Make another, but symlink one of the dirs
mkdir -p $tree2/etc/pki/rpm-gpg
ln -rs $tree1/etc/pki/ca-trust $tree2/etc/pki/ca-trust
echo "TREE2" > $tree2/etc/tree-id

# OK, show what we've got set up.
cd $tmpdir
set -x
find * -ls
cat tree1/etc/tree-id           # "TREE1"
cat tree2/etc/tree-id           # "TREE2"

# You might think these would all be the same file, but.. nope!
cd tree2/etc; cat tree-id       # "TREE2"
cd pki;       cat ../tree-id    # "TREE2"
cd ca-trust;  cat ../../tree-id # "TREE1" (!)

{ set +x; } 2>/dev/null