From 0a6a4938fde589fe8f2160fc542428ef100153ce Mon Sep 17 00:00:00 2001
From: Keewis <keewis@posteo.de>
Date: Tue, 3 Dec 2019 17:49:08 +0100
Subject: [PATCH 1/4] add the project root to PYTHONPATH and sys.path

---
 doc/conf.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/doc/conf.py b/doc/conf.py
index 65635353e93..c1c9fd2718d 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -15,10 +15,15 @@
 
 import datetime
 import os
+import pathlib
 import subprocess
 import sys
 from contextlib import suppress
 
+root = pathlib.Path(__file__).absolute().parent.parent
+os.environ["PYTHONPATH"] = str(root)
+sys.path.insert(0, str(root))
+
 import xarray
 
 allowed_failures = set()

From 536864474194c70b78fbf8573665665ca9bf17ba Mon Sep 17 00:00:00 2001
From: Keewis <keewis@posteo.de>
Date: Tue, 3 Dec 2019 18:21:00 +0100
Subject: [PATCH 2/4] don't install the package

---
 readthedocs.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/readthedocs.yml b/readthedocs.yml
index 6429780e7d7..c64fa1b7b02 100644
--- a/readthedocs.yml
+++ b/readthedocs.yml
@@ -4,5 +4,5 @@ conda:
     file: ci/requirements/doc.yml
 python:
     version: 3.7
-    setup_py_install: true
+    setup_py_install: false
 formats: []

From 7f2dd387430cd5f9f13c04c957e21b87e16e1469 Mon Sep 17 00:00:00 2001
From: Keewis <keewis@posteo.de>
Date: Tue, 3 Dec 2019 18:30:25 +0100
Subject: [PATCH 3/4] update the requirements for the documentation environment

so we definitely trigger the version collision.
---
 ci/requirements/doc.yml | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/ci/requirements/doc.yml b/ci/requirements/doc.yml
index f2c09ed6fef..97488e7f581 100644
--- a/ci/requirements/doc.yml
+++ b/ci/requirements/doc.yml
@@ -6,7 +6,7 @@ dependencies:
   - python=3.7
   - bottleneck
   - cartopy
-  - eccodes
+  - cfgrib
   - h5netcdf
   - ipykernel
   - ipython
@@ -21,8 +21,5 @@ dependencies:
   - seaborn
   - sphinx
   - sphinx_rtd_theme
+  - xarray
   - zarr
-  - pip
-  - pip:
-    - cfgrib
-

From 1a075fe84273ef06942f43d38d6645cc8f042dd8 Mon Sep 17 00:00:00 2001
From: Keewis <keewis@posteo.de>
Date: Tue, 3 Dec 2019 19:55:29 +0100
Subject: [PATCH 4/4] comment on the reasons for the sys.path and os.environ
 modifications

---
 doc/conf.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/conf.py b/doc/conf.py
index c1c9fd2718d..11abda6bb63 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -20,6 +20,7 @@
 import sys
 from contextlib import suppress
 
+# make sure the source version is preferred (#3567)
 root = pathlib.Path(__file__).absolute().parent.parent
 os.environ["PYTHONPATH"] = str(root)
 sys.path.insert(0, str(root))