You do not say at what stage you see this but I guess your locale is different from en_US.UTF-8 … changing locale probably requires root.
You might check these links and see what workaround might fit your situation.
- https://stackoverflow.com/questions/55077450/linode-lish-bash-warning-setlocale-lc-all-cannot-change-locale-en-us-utf-8
- https://askubuntu.com/questions/114759/warning-setlocale-lc-all-cannot-change-locale
Part of your error also fits with a bug seen in Snap [1]
[1] Cannot get the easy installer to work on Ubuntu latest version - #9 by nige