[davidfor]

Running from source, I am getting the following when using "Remove unused css rules" in the editor:

calibre, version 3.39.1
ERROR: Unhandled exception: <b>ImportError</b>:No module named markdown

calibre 3.39.1* [64bit]  embedded-python: True is64bit: True
Windows-10-10.0.17134-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.17134')
Python 2.7.15+
Windows: ('10', '10.0.17134', 'SP0', u'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: DeDRM (6, 0, 9) && Wikidata (1, 3, 0) && Webscription (1, 1, 2) && KoboTouchBeta (2, 3, 4) && Manage Series (1, 2, 8) && KoboTouchTOCUpdate (0, 1, 15) && Count Pages (1, 8, 2) && GetFileName (0, 0, 13) && Favourites Menu (1, 0, 4) && Embed Comic Metadata (1, 4, 0) && Fantastic Fiction Adults (1, 1, 0) && KoboTouchExtended (3, 0, 2) && Annotations (1, 8, 6) && Kobo Books (1, 5, 0) && SmartEject (2, 2, 0) && Modify ePub (1, 3, 13) && Resize Cover (1, 0, 2) && Find Duplicates (1, 6, 3) && Walk Search History (1, 201, 0) && Set KFX metadata (from KFX Output) (1, 27, 0) && KFX Output (1, 27, 0) && Skoob (1, 2, 2) && Comicvine (0, 10, 7) && KePub Metadata Reader (3, 0, 2) && Kobo Utilities (2, 6, 4) && Modify SOL Story (0, 8, 4) && Reading List (1, 6, 6) && User Category (1, 5, 3) && Databazeknih (1, 4, 11) && DOC Input (1, 0, 1) && KePub Input (3, 0, 0) && Kindle 2, 3, 4, Touch, PaperWhite, Voyage Device Interface MBP Update Mod (1, 0, 0) && Open With (1, 5, 10) && Quality Check (1, 9, 11) && KePub Output (3, 0, 0) && Google Scholar (0, 1, 1) && EpubMerge (2, 5, 0) && Ex Libris (1, 0, 19) && Martinus.sk (2018, 3, 30) && Goodreads (1, 4, 0) && Clipboard Search (1, 3, 1) && View Manager (1, 4, 3) && Kobo Import (1, 0, 0) && KePub Metadata Writer (3, 0, 3) && Obok DeDRM (3, 1, 6) && FanFicFare (3, 5, 0) && Modify SOL Story (0, 8, 4) && Goodreads Sync (1, 12, 1) && Hyphenate This! (0, 0, 8) && Overdrive Link (2, 32, 0) && Generate Cover (1, 5, 21) && LubimyCzytac (2, 0, 31) && Unplugged (1, 0, 0) && EpubSplit (2, 6, 0) && Sort CSS (0, 2, 1) && Diaps Editing Toolbag (0, 3, 5) && FictionDB (1, 1, 0) && Import List (1, 3, 1) && WorldsWithoutEnd (0, 0, 1) && Smashwords Metadata (0, 0, 3) && Fantastic Fiction (1, 3, 0) && NormComment (0, 0, 2)
Traceback (most recent call last):
  File "E:\Development\GitHub\calibre\src\calibre\gui2\tweak_book\boss.py", line 593, in polish
  File "E:\Development\GitHub\calibre\src\calibre\gui2\tweak_book\polish.py", line 85, in show_report
  File "E:\Development\GitHub\calibre\src\calibre\gui2\tweak_book\polish.py", line 79, in format_report
  File "E:\Development\GitHub\calibre\src\calibre\startup.py", line 51, in load_module
  File "importlib\__init__.py", line 37, in import_module
ImportError: No module named markdown

And a lot of the metadata source plugins are giving:

Error parsing comments for url: 'https://webcache.googleusercontent.com/search?q=cache:CG_Km3yRNn0J:https://www.amazon.com/Dominion-Rising-Omnibus-Books-1-3-ebook/dp/B07JQ7LHSY+&cd=1&hl=en&ct=clnk&gl=au'
Traceback (most recent call last):
  File "E:\Development\GitHub\calibre\src\calibre\ebooks\metadata\sources\amazon.py", line 379, in parse_details
  File "E:\Development\GitHub\calibre\src\calibre\ebooks\metadata\sources\amazon.py", line 588, in parse_comments
  File "E:\Development\GitHub\calibre\src\calibre\ebooks\metadata\sources\amazon.py", line 573, in _render_comments
  File "E:\Development\GitHub\calibre\src\calibre\library\comments.py", line 150, in sanitize_comments_html
  File "E:\Development\GitHub\calibre\src\calibre\startup.py", line 51, in load_module
  File "importlib\__init__.py", line 37, in import_module
ImportError: No module named markdown

I can see https://github.com/kovidgoyal/calibr...f7e9e110458f3b has removed markdown from the source, and a couple of later changes add some handling for importing the Markdown module. But, I don't see the replacement. Is this something that needs to be built and installed as part of the release? Or am I missing something in my environment?