[Editor Plugin] EpubCheck

[Doitsu]

This thread is not intended for discussing the pros and cons of using EPUBCheck or best practices.

@ryder please ask questions about best practices in the ePub forum.

I'll ask the mods to hide future posts that are not about installing or using the Calibre EPUBCheck plugin.

[Morea]

Hello!

I get an error message when starting this plugin:

Traceback (most recent call last):
File "calibre_plugins.epub_check.main", line 387, in ask_user
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfc in position 28: invalid start byte

The version of Calibre doesn't matter. I uninstalled and reinstalled the plugin with the same result.

Hope you can help.

Morea

[JSWolf]

Originally Posted by Morea

Hello!

I get an error message when starting this plugin:



The version of Calibre doesn't matter. I uninstalled and reinstalled the plugin with the same result.

Hope you can help.

Morea

Are you using the latest 64-bit version of Java? If it's any 32-bit version of Java, then you will have a problem.

[Morea]

Originally Posted by JSWolf

Are you using the latest 64-bit version of Java? If it's any 32-bit version of Java, then you will have a problem.

Yes, I am using OpenJDK Runtime Environment Temurin-21.0.5+11 (build 21.0.5+11-LTS) 64 bit.

BUT the user settings of my Calibre installation come from an older installation of Calibre - and perhaps that was a 32-bit installation...

[Doitsu]

Originally Posted by Morea

I get an error message when starting this plugin

The error message is usually displayed because EPUBCheck generated invalid UTF-8 output. This usually happens if the epub file contains files that aren't valid UTF-8 files.

To fix this problem:

• uninstall the plugin
• re-download the plugin if you didn't save it
• extract main.py from the zip file
• search for and change the following two lines:
  

              stdout = result[0].decode('utf-8')
              stderr = result[1].decode('utf-8')

  to:
  

              stdout = result[0].decode('utf-8', errors='ignore')
              stderr = result[1].decode('utf-8', errors='ignore')

• replace main.py in the zip file with the modified version
• re-install the plugin from the .zip file

If you're getting more Python errors, open the book with Calibre Editor, select Tools > Fix HTML - all files followed by Tools > Beautify all files, save the epub and re-run the EpubCheck plugin.

[JSWolf]

Originally Posted by Doitsu

The error message is usually displayed because EPUBCheck generated invalid UTF-8 output. This usually happens if the epub file contains files that aren't valid UTF-8 files.

To fix this problem:

• uninstall the plugin
• re-download the plugin if you didn't save it
• extract main.py from the zip file
• search for and change the following two lines:
  

              stdout = result[0].decode('utf-8')
              stderr = result[1].decode('utf-8')

  to:
  

              stdout = result[0].decode('utf-8', errors='ignore')
              stderr = result[1].decode('utf-8', errors='ignore')

• replace main.py in the zip file with the modified version
• re-install the plugin from the .zip file

If you're getting more Python errors, open the book with Calibre Editor, select Tools > Fix HTML - all files followed by Tools > Beautify all files, save the epub and re-run the EpubCheck plugin.

Does this mean there will be a new version?

[DNSB]

Personally, if I get an error message indicating that an ePub files contains encoding that is not UTF-8 or UTF-16 (I've seen 2 ePubs in my entire involvement with ereading that were UTF-16 encoded), that ePub is not standards compliant and should be fixed. As section 3.9 of the ePub 3.3 recommendation states:

MUST be encoded in UTF-8 or UTF-16 [unicode], with UTF-8 as the RECOMMENDED encoding.

While the ePub 2.0.1 Open Publication Structure document 1.4.1.2 states:

A conformant XHTML Content Document must meet these conditions:
it is a well-formed XML document (as defined by XML 1.0); and
it is encoded in UTF-8 or UTF-16; and

I will admit that I have seen several ePubs where the creator did not use UTF-8 or UTF-16 but again, they are not standards compliant and were often the result of an amateur converting book formats or converting an OCR scan of a pbook to an ePub document.

[Morea]

open the book with Calibre Editor, select Tools > Fix HTML - all files followed by Tools > Beautify all files, save the epub and re-run the EpubCheck plugin.

This didn't help, and it could not, since this problem even occurs with books that I know to be 100% error-free.

I did not try to fix the plugin's main.py, since I used the epubcheck plugin in the version 4.26 for some years and never got such a crash. I suppose there is something new in Windows 11 that was no problem in Windows 10 all these years...

[Morea]

Now I fixed the plugin's main.py as you described and: yes! It works like charm, with the old 4.26 epubcheck version and the new 5.12 one!

This is the fixed zip:
https://www.mobileread.com/forums/at...1&d=1741082768

Thank you!