From 0bddbb67ad852dabb08441a47156351f035b53ed Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 14 May 2017 21:55:59 +0530
Subject: [PATCH] Allow running calibre in debug mode via an environment
 variable

---
 src/calibre/constants.py  | 2 +-
 src/calibre/debug.py      | 1 -
 src/calibre/gui_launch.py | 4 ++++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/calibre/constants.py b/src/calibre/constants.py
index 7ae4491ff0..07dc7d1533 100644
--- a/src/calibre/constants.py
+++ b/src/calibre/constants.py
@@ -87,7 +87,7 @@ else:
         filesystem_encoding = 'utf-8'
 
 
-DEBUG = False
+DEBUG = b'CALIBRE_DEBUG' in os.environ
 
 
 def debug():
diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index 2838d0a3e7..8600638274 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -250,7 +250,6 @@ def main(args=sys.argv):
     opts, args = option_parser().parse_args(args)
     if opts.gui:
         from calibre.gui_launch import calibre
-        print_basic_debug_info()
         calibre(['calibre'])
     elif opts.gui_debug is not None:
         run_debug_gui(opts.gui_debug)
diff --git a/src/calibre/gui_launch.py b/src/calibre/gui_launch.py
index ba6d2a3eed..16f54916d4 100644
--- a/src/calibre/gui_launch.py
+++ b/src/calibre/gui_launch.py
@@ -63,6 +63,10 @@ def register_with_default_programs():
 
 
 def calibre(args=sys.argv):
+    from calibre.constants import DEBUG
+    if DEBUG:
+        from calibre.debug import print_basic_debug_info
+        print_basic_debug_info()
     detach_gui()
     init_dbus()
     with register_with_default_programs():