From 616c2a2964feea213d829f5f1c946cd6fd73bd57 Mon Sep 17 00:00:00 2001
From: micbou <contact@micbou.com>
Date: Tue, 22 Jan 2019 13:10:46 +0100
Subject: [PATCH] Improve error message when unable to load Python

Check explicitely that Vim is compiled with Python support.
Attempt to load Python 3 before Python 2 since only one can be loaded at
a time on some platforms. Return an appropriate error if unable to load
both.
---
 plugin/youcompleteme.vim | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/plugin/youcompleteme.vim b/plugin/youcompleteme.vim
index 3cc57480..1f77e050 100644
--- a/plugin/youcompleteme.vim
+++ b/plugin/youcompleteme.vim
@@ -54,13 +54,22 @@ elseif !has( 'timers' )
         \ echohl None
   call s:restore_cpo()
   finish
-elseif !has( 'python' ) && !has( 'python3' )
+elseif !has( 'python_compiled' ) && !has( 'python3_compiled' )
   echohl WarningMsg |
         \ echomsg "YouCompleteMe unavailable: requires Vim compiled with " .
         \ "Python (2.7.1+ or 3.4+) support." |
         \ echohl None
   call s:restore_cpo()
   finish
+" These calls try to load the Python 2 and Python 3 libraries when Vim is
+" compiled dynamically against them. Since only one can be loaded at a time on
+" some platforms, we first check if Python 3 is available.
+elseif !has( 'python3' ) && !has( 'python' )
+  echohl WarningMsg |
+        \ echomsg "YouCompleteMe unavailable: unable to load Python." |
+        \ echohl None
+  call s:restore_cpo()
+  finish
 elseif &encoding !~? 'utf-\?8'
   echohl WarningMsg |
         \ echomsg "YouCompleteMe unavailable: requires UTF-8 encoding. " .