Assuming a bash interactive environment will be correctly formed on login, we
should prefer to probe the environment using a shell that reports itself as
`bash` instead of `sh` which may not source files that set the
environment modules in statements like:
```
case "$is" in
bash) test -s /etc/bash.bashrc.local && . /etc/bash.bashrc.local ;;
ksh) test -s /etc/ksh.kshrc.local && . /etc/ksh.kshrc.local ;;
zsh) test -s /etc/zsh.zshrc.local && . /etc/zsh.zshrc.local ;;
ash) test -s /etc/ash.ashrc.local && . /etc/ash.ashrc.local
esac
test -s /etc/sh.shrc.local && . /etc/sh.shrc.local
```