Apache 2.4 conditional htpasswd auth depending on host

.htaccess

<IfModule mod_setenvif.c>
    SetEnvIfNoCase ^HOST$ .+ unauthenticated
    SetEnvIfNoCase ^HOST$ ^dev\.example\.com$ !unauthenticated

    AuthType Basic
    AuthName "dev.example.com"
    AuthUserFile /path/to/.htpasswd
    <RequireAny>
        Require env unauthenticated
        Require valid-user
    </RequireAny>
</IfModule>