gistfile1.diff

diff --git a/autoload/necoghc.vim b/autoload/necoghc.vim
index 9b43ec8..d1d35e6 100644
--- a/autoload/necoghc.vim
+++ b/autoload/necoghc.vim
@@ -202,9 +202,17 @@ function! s:get_modules() "{{{
 endfunction "}}}
 
 function! s:ghc_mod(cmd)  "{{{
+  let l:cmd = 'ghc-mod -g -package -g ghc ' . a:cmd
   lcd `=expand('%:p:h')`
-  let l:ret = system('ghc-mod -g -package -g ghc ' . a:cmd)
+  let l:ret = system(l:cmd)
   lcd -
+  let l:logs = []
+  let l:logfile = 'system.log'
+  if filereadable(l:logfile)
+    let l:logs = readfile(l:logfile)
+  endif
+  let l:logs += [l:cmd, l:ret]
+  call writefile(l:logs, l:logfile)
   return split(l:ret, '\n')
 endfunction "}}}