From 3b0fa0c05d4a495c295de3a3216182727578d356 Mon Sep 17 00:00:00 2001
From: jack1142 <6032823+jack1142@users.noreply.github.com>
Date: Tue, 22 Oct 2019 04:43:00 +0200
Subject: [PATCH] [Core/Downloader] Add 3rd-party lib folder to `sys.path`
 before loading cogs (#3062)

* fix(core,downloader): add lib folder to sys.path before loading cogs

* chore(changelog): add towncrier entry

* fix(core): always append 3rd-party lib path to the end of `sys.path`
---
 changelog.d/3036.bugfix.rst          | 1 +
 changelog.d/3062.bugfix.rst          | 1 +
 redbot/__main__.py                   | 7 +++++++
 redbot/cogs/downloader/downloader.py | 4 ----
 4 files changed, 9 insertions(+), 4 deletions(-)
 create mode 100644 changelog.d/3036.bugfix.rst
 create mode 100644 changelog.d/3062.bugfix.rst

diff --git a/changelog.d/3036.bugfix.rst b/changelog.d/3036.bugfix.rst
new file mode 100644
index 000000000..29fc8ae1d
--- /dev/null
+++ b/changelog.d/3036.bugfix.rst
@@ -0,0 +1 @@
+Add 3rd-party lib folder to ``sys.path`` before loading cogs. This prevents issues with 3rd-party cogs failing to load without loaded Downloader due to unavailable requirements.
\ No newline at end of file
diff --git a/changelog.d/3062.bugfix.rst b/changelog.d/3062.bugfix.rst
new file mode 100644
index 000000000..5b4147525
--- /dev/null
+++ b/changelog.d/3062.bugfix.rst
@@ -0,0 +1 @@
+Always append 3rd-party lib folder to the end of ``sys.path`` to avoid shadowing Red's dependencies.
\ No newline at end of file
diff --git a/redbot/__main__.py b/redbot/__main__.py
index 042294952..a195e26a4 100644
--- a/redbot/__main__.py
+++ b/redbot/__main__.py
@@ -119,6 +119,13 @@ def main():
     init_global_checks(red)
     init_events(red, cli_flags)
 
+    # lib folder has to be in sys.path before trying to load any 3rd-party cog (GH-3061)
+    # We might want to change handling of requirements in Downloader at later date
+    LIB_PATH = data_manager.cog_data_path(raw_name="Downloader") / "lib"
+    LIB_PATH.mkdir(parents=True, exist_ok=True)
+    if str(LIB_PATH) not in sys.path:
+        sys.path.append(str(LIB_PATH))
+
     red.add_cog(Core(red))
     red.add_cog(CogManagerUI())
     if cli_flags.dev:
diff --git a/redbot/cogs/downloader/downloader.py b/redbot/cogs/downloader/downloader.py
index a7f85074c..d8a21d00d 100644
--- a/redbot/cogs/downloader/downloader.py
+++ b/redbot/cogs/downloader/downloader.py
@@ -43,15 +43,11 @@ class Downloader(commands.Cog):
         self.SHAREDLIB_PATH = self.LIB_PATH / "cog_shared"
         self.SHAREDLIB_INIT = self.SHAREDLIB_PATH / "__init__.py"
 
-        self.LIB_PATH.mkdir(parents=True, exist_ok=True)
         self.SHAREDLIB_PATH.mkdir(parents=True, exist_ok=True)
         if not self.SHAREDLIB_INIT.exists():
             with self.SHAREDLIB_INIT.open(mode="w", encoding="utf-8") as _:
                 pass
 
-        if str(self.LIB_PATH) not in syspath:
-            syspath.insert(1, str(self.LIB_PATH))
-
         self._repo_manager = RepoManager()
 
     async def initialize(self):