Cleaner error handling for pylint.

syntax_checkers/python/pylint.vim

@@ -7,18 +7,19 @@
 if exists("g:loaded_syntastic_python_pylint_checker")
     finish
 endif
-let g:loaded_syntastic_python_pylint_checker=1
+let g:loaded_syntastic_python_pylint_checker = 1
+
+let s:pylint_new = -1
 
 function! SyntaxCheckers_python_pylint_IsAvailable()
-    return executable('pylint')
+    let s:pylint_new = executable('pylint') ? s:PylintNew() : -1
+    return s:pylint_new >= 0
 endfunction
 
 function! SyntaxCheckers_python_pylint_GetLocList()
-    let pylint_new = s:PylintNew()
-
     let makeprg = syntastic#makeprg#build({
         \ 'exe': 'pylint',
-        \ 'args': (pylint_new ? '--msg-template="{path}:{line}: [{msg_id}] {msg}" -r n' : '-f parseable -r n -i y'),
+        \ 'args': (s:pylint_new ? '--msg-template="{path}:{line}: [{msg_id}] {msg}" -r n' : '-f parseable -r n -i y'),
         \ 'filetype': 'python',
         \ 'subchecker': 'pylint' })
 
@@ -51,10 +52,12 @@ endfunction
 function s:PylintNew()
     try
         let pylint_version = filter(split(system('pylint --version'), '\m, \|\n'), 'v:val =~# "^pylint"')[0]
-        return syntastic#util#versionIsAtLeast(syntastic#util#parseVersion(pylint_version), [1])
+        let ret = syntastic#util#versionIsAtLeast(syntastic#util#parseVersion(pylint_version), [1])
     catch /E684/
-        return 0
+        call syntastic#util#error("checker python/pylint: can't parse version string (abnormal termination?)")
+        let ret = -1
     endtry
+    return ret
 endfunction
 
 call g:SyntasticRegistry.CreateAndRegisterChecker({