ebook-convert stuck unless using --max-levels=0

[a914]

Hello everyone,

I'm new to Calibre and have a hard time to get started on conversion.
My setup is plain vanilla Windows 10 Pro 22H2 / calibre 64 bit 6.13.0.
I have a local copy of the entire https://www.projekt-gutenberg.org/ collection (some 7 GB) as HTLM and some fraction of it should go to my Tolino as epub.

I figured converting the entire repository is a bit going over the top, so I tried a single author - and failed. Tried a single book of that author - and failen.
This means, I tried 'Add books from folders and subfolders', or just 'Add books from a single folder', but to no avail.

I boiled it down to use the command line version, i.e. ebook-convert:
ebook-convert "E:\Gutenberg-DE\Edition 15\anzengru\erzaehlg\erzaehlg.html" "E:\tmp\temp.epub" --language=de

As the process would hang forever, you notice I interrupted at some point.
Thius, even adding -d -vv did not yield any diagnostics output.

Now, if additionally specifying --max-levels=0, conversion works like a charm.

I have a vague idea why that might be required, but where to add this option or tweak the corresponding parameter in Calibre?

Any thoughts will be highly appreciated.

Thanks,
a914

Detail:

getting stuck

C:\Users\guest>ebook-convert "E:\Gutenberg-DE\Edition 15\anzengru\erzaehlg\erzaehlg.html" "E:\tmp\temp.epub" -vv -d --language=de
Conversion options changed from defaults:
  language: 'de'
1% Eingabe wird zu HTML konvertiert*…
InputFormatPlugin: HTML Input running
on E:\Edition 15\Edition15\anzengru\erzaehlg\erzaehlg.html
Building file list...
Traceback (most recent call last):
  File "runpy.py", line 196, in _run_module_as_main
  File "runpy.py", line 86, in _run_code
  File "site.py", line 83, in <module>
  File "site.py", line 78, in main
  File "site.py", line 50, in run_entry_point
  File "calibre\ebooks\conversion\cli.py", line 419, in main
  File "calibre\ebooks\conversion\plumber.py", line 1108, in run
  File "calibre\customize\conversion.py", line 242, in __call__
  File "calibre\ebooks\conversion\plugins\html_input.py", line 90, in convert
  File "calibre\ebooks\conversion\plugins\html_input.py", line 153, in create_oebbook
  File "calibre\ebooks\html\input.py", line 287, in get_filelist
  File "calibre\ebooks\html\input.py", line 265, in traverse
  File "calibre\ebooks\html\input.py", line 144, in __init__
  File "calibre\ebooks\html\input.py", line 159, in find_links
KeyboardInterrupt
^C

running fine when adding --max-levels=0

C:\Users\guest>ebook-convert "E:\Gutenberg-DE\Edition15\anzengru\erzaehlg\erzaehlg.html" "E:\tmp\temp.epub" --language=de -d -vv  --max-levels=0
Conversion options changed from defaults:
  debug_pipeline: '-vv'
  language: 'de'
  max_levels: 0.0
1% Converting input to HTML...
InputFormatPlugin: HTML Input running
on E:\Gutenberg-DE\Edition15\anzengru\erzaehlg\erzaehlg.html
Building file list...
Normalizing filename cases
Rewriting HTML links
Forcing erzaehlg.html into XHTML namespace
CSSStyleRule: No start { of style declaration found: '.pageref\n\n\n' [543:1: ]
CSSStyleRule: No style declaration or "}" found: '.pageref\n\n\n'
Forcing allworka.html into XHTML namespace
Forcing autor-az.html into XHTML namespace
Input debug saved to: C:\Users\guest\-vv\input
Parsed HTML written to: C:\Users\guest\-vv\parsed
34% Running transforms on e-book...
Merging user specified metadata...
Detecting structure...
        Detected chapter: Ludwig Anzengruber Kleinere ErzählungenSammlung au
        Detected chapter: Ein Mann, den Gott liebt Florian Traidmann hieß da
        Detected chapter: Vom Hanns und der Gretl Dort, wo der Wald niederge
        Detected chapter: Teufelsträume 1873 Ein dichter Nebel lag über der
Auto generated TOC with 41 entries.
Structured HTML written to: C:\Users\guest\-vv\structure
Flattening CSS and remapping font sizes...
Source base font size is 12.00000pt
Removing fake margins...
Cleaning up manifest...
Trimming unused files from manifest...
Processed HTML written to: C:\Users\guest\-vv\processed
Creating EPUB Output...
67% Running EPUB Output plugin
Splitting markup on page breaks and flow limits, if any...
        Looking for large trees in erzaehlg.html...
        No large trees found
        Split into 6 parts
Generating default cover
EPUB output written to E:\tmp\temp.epub
Output saved to   E:\tmp\temp.epub

C:\Users\guest>

[kovidgoyal]

adding books does not convert unless you have that option set in the calibre adding preferences. And any command line conversion option is present in the GUI as well in Preferences->Conversion->Common options