Problem

If a command is set to lazy-load a plugin, running it with arguments won't load the plugin because the wrapper command created by zpack does not accept arguments by default.

For instance, with the spec:

return {
    'ibhagwan/fzf-lua',
    cmd = 'FzfLua',
    config = function ()
        require('fzf-lua').setup { }
    end,
}

Running :FzfLua will load the plugin correctly, whereas :FzfLua files will error with E488: Trailing characters: files.

Solution

According to :h :command-nargs:

By default, a user defined command will take no arguments (and an error is reported if any are supplied). However, it is possible to specify that the command can take arguments, using the -nargs attribute.

Setting nargs = '*' in the opts field of the zpack command wrapper fixes the issue.