explicitly export LC_ALL for sphinx builds (#2708)

Co-authored-by: Bouwe Andela <[email protected]>

Author: valeriupredoi

doc/conf.py

@@ -113,7 +113,11 @@
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-# language = None
+# language = "en"
+# a lot of issues with importing esmvalcore modules due to
+# "incorrect" locale settings' this looks like a fix
+import locale
+locale.setlocale(locale.LC_ALL, 'C')
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used: