fix rtd version (SciTools#4855)

Author: bjlittle

.readthedocs.yml

@@ -4,6 +4,10 @@ build:
   os: ubuntu-20.04
   tools:
     python: mambaforge-4.10
+  jobs:
+    post_checkout:
+      - git fetch --unshallow
+      - git fetch --all
 
 conda:
   environment: requirements/ci/readthedocs.yml

docs/src/conf.py

@@ -87,6 +87,8 @@ def autolog(message):
 # |version|, also used in various other places throughout the built documents.
 
 version = get_version("scitools-iris")
+if version.endswith("+dirty"):
+    version = version[: -len("+dirty")]
 autolog(f"Iris Version = {version}")
 
 # -- General configuration ---------------------------------------------------