I am having the same problem, using Calibre on the Mac. Every time I try to convert an HTML file into ANY ebook format I get a spine is empty error. I have my HTML file in UTF-8 but that didn't help.
Any idea what's going on? I'd be happy to provide you with the original HTML file, kovidgoyal, if that will help.
Thanks,
Guido
ERROR: Conversion Error: <b>Failed</b>: Convert book 1 of 1 (DemonsNight)
Convert book 1 of 1 (DemonsNight)
Processing archive...
Resolved conversion options
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'breadth_first': False,
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., 'chapter|book|section|part\\s+', 'i')) or @class = 'chapter']",
'chapter_mark': u'pagebreak',
'comments': None,
'cover': None,
'debug_pipeline': None,
'disable_font_rescaling': False,
'dont_justify': False,
'dont_package': False,
'extra_css': None,
'font_size_mapping': None,
'footer_regex': u'(?i)(?<=<hr>)((\\s*<a name=\\d+></a>((<img.+?>)*<br>\\s*)?\\d+<br>\\s*.*?\\s*)|(\\s* <a name=\\d+></a>((<img.+?>)*<br>\\s*)?.*?<br>\\s*\\d+))(?=<br>)' ,
'header_regex': u'(?i)(?<=<hr>)((\\s*<a name=\\d+></a>((<img.+?>)*<br>\\s*)?\\d+<br>\\s*.*?\\s*)|(\\s* <a name=\\d+></a>((<img.+?>)*<br>\\s*)?.*?<br>\\s*\\d+))(?=<br>)' ,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x63f0b50>,
'insert_blank_line': False,
'insert_metadata': False,
'isbn': None,
'language': None,
'level1_toc': None,
'level2_toc': None,
'level3_toc': None,
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'max_levels': 5,
'max_toc_links': 50,
'no_chapters_in_toc': False,
'no_inline_navbars': False,
'output_profile': <calibre.customize.profiles.OutputProfile object at 0x63f0d10>,
'page_breaks_before': u"//*[name()='h1' or name()='h2']",
'prefer_metadata_cover': False,
'preprocess_html': False,
'pretty_print': False,
'publisher': None,
'rating': None,
'read_metadata_from_opf': '/var/folders/rX/rXWGE5kyEK0nkF0NIl6GnU+++TI/-Tmp-/calibre_0.6.37_SAlIls.opf',
'remove_first_image': False,
'remove_footer': False,
'remove_header': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'series': None,
'series_index': None,
'tags': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 6,
'unwrap_factor': 0.0,
'use_auto_toc': False,
'verbose': 2}
Python function terminated unexpectedly: Spine is empty
InputFormatPlugin: HTML Input running
on /var/folders/rX/rXWGE5kyEK0nkF0NIl6GnU+++TI/-Tmp-/calibre_0.6.37_c0GICZ_plumber/content.opf
Parsing all content...
Manifest item 'toc.ncx' not found
Traceback (most recent call last):
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 147, in main
return run_entry_point()
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 116, in run_entry_point
return getattr(pmod, func)()
File "site-packages/calibre/utils/ipc/worker.py", line 99, in main
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 24, in gui_convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 745, in run
File "site-packages/calibre/customize/conversion.py", line 211, in __call__
File "site-packages/calibre/ebooks/html/input.py", line 291, in convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 877, in create_oebbook
File "site-packages/calibre/ebooks/oeb/reader.py", line 72, in __call__
File "site-packages/calibre/ebooks/oeb/reader.py", line 589, in _all_from_opf
File "site-packages/calibre/ebooks/oeb/reader.py", line 289, in _spine_from_opf
calibre.ebooks.oeb.base.OEBError: Spine is empty