diff --git a/autoload/rhubarb.vim b/autoload/rhubarb.vim
index 31ae42e..d794932 100644
--- a/autoload/rhubarb.vim
+++ b/autoload/rhubarb.vim
@@ -201,19 +201,23 @@ function! rhubarb#Request(path, ...) abort
               \ { r -> r.exit_status || r.stdout ==# [''] ? '' : call(options.callback, [json_decode(join(r.stdout, ' '))] + get(options, 'callback_args', [])) })
       endif
       let raw = join(FugitiveExecute({'argv': args}).stdout, ' ')
-      return empty(raw) ? raw : json_decode(raw)
+      if empty(raw)
+        throw 'rhubarb: bug? empty response from ' . path
+      else
+        return json_decode(raw)
+      endif
     catch /^fugitive:/
     endtry
   endif
-  let raw = system(join(map(copy(args), 's:shellesc(v:val)'), ' '))
+  silent let raw = system(join(map(copy(args), 's:shellesc(v:val)'), ' '))
   if has_key(options, 'callback')
     if !v:shell_error && !empty(raw)
       call call(options.callback, [rhubarb#JsonDecode(raw)] + get(options, 'callback_args', []))
     endif
     return {}
   endif
-  if raw ==# ''
-    return raw
+  if empty(raw)
+    throw 'rhubarb: bug? empty response from ' . path
   else
     return rhubarb#JsonDecode(raw)
   endif
@@ -263,9 +267,7 @@ function! rhubarb#Complete(findstart, base) abort
         let query = a:base
       endif
       let response = rhubarb#RepoSearch('issues', 'state:open '.query)
-      if type(response) != type({})
-        call s:throw('unknown error')
-      elseif has_key(response, 'message')
+      if has_key(response, 'message')
         call s:throw(response.message)
       else
         let issues = get(response, 'items', [])