--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -19,6 +19,10 @@
 "
 " If cleanup after each Test_ function is needed, define a TearDown function.
 " It will be called after each Test_ function.
+"
+" When debugging a test it can be useful to add messages to v:errors:
+" 	call add(v:errors, "this happened")
+
 
 " Without the +eval feature we can't run these tests, bail out.
 so small.vim
@@ -65,21 +69,21 @@ endfunc
 
 
 " Source the test script.  First grab the file name, in case the script
-" navigates away.
-let testname = expand('%')
-let done = 0
-let fail = 0
-let errors = []
-let messages = []
+" navigates away.  g:testname can be used by the tests.
+let g:testname = expand('%')
+let s:done = 0
+let s:fail = 0
+let s:errors = []
+let s:messages = []
 if expand('%') =~ 'test_viml.vim'
-  " this test has intentional errors, don't use try/catch.
+  " this test has intentional s:errors, don't use try/catch.
   source %
 else
   try
     source %
   catch
-    let fail += 1
-    call add(errors, 'Caught exception: ' . v:exception . ' @ ' . v:throwpoint)
+    let s:fail += 1
+    call add(s:errors, 'Caught exception: ' . v:exception . ' @ ' . v:throwpoint)
   endtry
 endif
 
@@ -88,27 +92,26 @@ set nomore
 redir @q
 function /^Test_
 redir END
-let tests = split(substitute(@q, 'function \(\k*()\)', '\1', 'g'))
+let s:tests = split(substitute(@q, 'function \(\k*()\)', '\1', 'g'))
 
 " Execute the tests in alphabetical order.
- for test in sort(tests)
+ for s:test in sort(s:tests)
   if exists("*SetUp")
     call SetUp()
   endif
 
-  call add(messages, 'Executing ' . test)
-  let done += 1
+  call add(s:messages, 'Executing ' . s:test)
+  let s:done += 1
   try
-    exe 'call ' . test
+    exe 'call ' . s:test
   catch
-    let fail += 1
-    call add(v:errors, 'Caught exception in ' . test . ': ' . v:exception . ' @ ' . v:throwpoint)
+    call add(v:errors, 'Caught exception in ' . s:test . ': ' . v:exception . ' @ ' . v:throwpoint)
   endtry
 
   if len(v:errors) > 0
-    let fail += 1
-    call add(errors, 'Found errors in ' . test . ':')
-    call extend(errors, v:errors)
+    let s:fail += 1
+    call add(s:errors, 'Found errors in ' . s:test . ':')
+    call extend(s:errors, v:errors)
     let v:errors = []
   endif
 
@@ -117,35 +120,36 @@ let tests = split(substitute(@q, 'functi
   endif
 endfor
 
-if fail == 0
+if s:fail == 0
   " Success, create the .res file so that make knows it's done.
-  exe 'split ' . fnamemodify(testname, ':r') . '.res'
+  exe 'split ' . fnamemodify(g:testname, ':r') . '.res'
   write
 endif
 
-if len(errors) > 0
+if len(s:errors) > 0
   " Append errors to test.log
   split test.log
   call append(line('$'), '')
-  call append(line('$'), 'From ' . testname . ':')
-  call append(line('$'), errors)
+  call append(line('$'), 'From ' . g:testname . ':')
+  call append(line('$'), s:errors)
   write
 endif
 
-let message = 'Executed ' . done . (done > 1 ? ' tests': ' test')
+let message = 'Executed ' . s:done . (s:done > 1 ? ' tests' : ' test')
 echo message
-call add(messages, message)
-if fail > 0
-  let message = fail . ' FAILED'
+call add(s:messages, message)
+if s:fail > 0
+  let message = s:fail . ' FAILED:'
   echo message
-  call add(messages, message)
+  call add(s:messages, message)
+  call extend(s:messages, s:errors)
 endif
 
 " Append messages to "messages"
 split messages
 call append(line('$'), '')
-call append(line('$'), 'From ' . testname . ':')
-call append(line('$'), messages)
+call append(line('$'), 'From ' . g:testname . ':')
+call append(line('$'), s:messages)
 write
 
 qall!