I tried to install the latest appimagetool release like this:

cd ~/.local/bin
wget 'https://github.com/AppImage/appimagetool/releases/download/continuous/appimagetool-x86_64.AppImage'
./appimagetool-x86_64.AppImage --appimage-extract
mv squashfs-root/ .appimagetool.appdir
ln -s appimagetool .appimagetool.appdir/AppRun

When calling appimagetool, as it is in the PATH, I get:

/home/user/.local/bin/appimagetool: 10: exec: /home/user/.local/bin/usr/bin/appimagetool: not found

I had a (very) old installation, installed in the same manner, and it worked right that without modifications:

appimagetool, continuous build (commit 672b3d0), build <local dev build> built on 2022-03-02 16:26:33 UTC

Comparing the old AppRun with the newer one led me to change the newer AppRun version like this:

SELF=$(readlink -f "$0")
this_dir=${SELF%/*}
#this_dir="$(readlink -f "$(dirname "$0")")"

appimagetool, continuous build (git version 7cfafc4), build 251 built on 2025-06-01 16:06:33 UTC

Imo, the order of readlink and dirname is swapped. Was there a reason for that? It should be swapped back to avoid this issue.