vim: command map to two commands gives E488

Question

I'd like a Build command that starts a build independent of what build system is used.

command! -nargs=* Build :Makeshift<Bar>MakeshiftBuild <args>

gives me

E488: Trailing characters

Either one can be mapped and works, but the two of them produce the error. I tried -bar on my map. I cannot change Makeshift to use it.

The following works:

function! s:BuildFun(what2build)
    execute 'Makeshift'
    execute 'MakeshiftBuild '.a:what2build
endfunction
command! -nargs=* Build :call s:BuildFun(<q-args>)

Can someone clarify, why the one-liner does not work or how to make it work. Just to gain insight.

Answer 1

The answer is in the comment: Makeshift was defined without a -bar parameter. From vim help command:

-bar        The command can be followed by a "|" and another command.
            A "|" inside the command argument is not allowed then.
            Also checks for a " to start a comment.

In such cases there is no need to fork the plugin repo, because one can use the workaround with the function, as shown above. This is then the general solution, as pointed out in https://stackoverflow.com/a/3266791/1803897.