plugin: output error string instead of out

Author: bhcleek

plugin/go.vim

@@ -165,7 +165,7 @@ function! s:GoInstallBinaries(updateBinaries, ...)
           " first download the binary
           let [l:out, l:err] = go#util#Exec(l:get_cmd + [l:importPath])
           if l:err
-            call go#util#EchoError(printf('Error installing %s: %s', l:importPath, l:out))
+            call go#util#EchoError(printf('Error installing %s: %s', l:importPath, l:err))
           endif
 
           call call(Restore_modules, [])
@@ -185,7 +185,7 @@ function! s:GoInstallBinaries(updateBinaries, ...)
         " first download the binary
         let [l:out, l:err] = go#util#Exec(l:get_cmd + [l:importPath])
         if l:err
-          call go#util#EchoError(printf('Error downloading %s: %s', l:importPath, l:out))
+          call go#util#EchoError(printf('Error downloading %s: %s', l:importPath, l:err))
         endif
 
         " and then build and install it
@@ -196,7 +196,7 @@ function! s:GoInstallBinaries(updateBinaries, ...)
 
         let [l:out, l:err] = go#util#Exec(l:build_cmd)
         if l:err
-          call go#util#EchoError(printf('Error installing %s: %s', l:importPath, l:out))
+          call go#util#EchoError(printf('Error installing %s: %s', l:importPath, l:err))
         endif