[tex4ht] [bug #500] error message when using biblatex with htlatex

[Nasser M. Abbasi]

On 2/13/2021 6:55 AM, Kristian Debrabant wrote:

> 
> Currently, I get many error messages when using htlatex in connection with
> biblatex.
> 
> The following minimal example
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> \documentclass{article}
> \usepackage{biblatex}
> \begin{document}
> \end{document}
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 
> compiles well in latex and pdflatex (to an empty document), but with htlatex I
> get the error
> 
> "! Package biblatex Error: Patching 'ifthen' package failed."
> 
> (using miktex with all packages updated from CTAN, including  biblatex.sty
> from 2020/12/31 v3.16 and the biblatex.4ht version from (2019-12-20-14:01) ).
> 
> 

It works for me on Linux under textlive 2020 using  make4ht and htlatex.
No errors.

I tried it on Miktex 2.9 under windows 10, and it gives error.

=======================
downloading http://mirrors.concertpass.com/tex-archive/systems/win32/miktex/tm/packages/logreq.tar.lzma...
0.01 MB, 0.20 Mbit/s
extracting files from logreq.tar.lzma...
======================================================================
[ERROR]   htlatex: Compilation errors in the htlatex run
[ERROR]   htlatex: Filename     Line    Message
[ERROR]   htlatex: ?    3        Package biblatex Error: Patching 'ifthen' package failed.
[ERROR]   htlatex: ?    7        Undefined control sequence.
[ERROR]   htlatex: ?    7        LaTeX Error: Missing \begin{document} in `'.
This is pdfTeX, Version 3.14159265-2.6-1.40.21 (MiKTeX 21.1)
entering extended mode
[ERROR]   htlatex: Compilation errors in the htlatex run
[ERROR]   htlatex: Filename     Line    Message
[ERROR]   htlatex: ?    3        Package biblatex Error: Patching 'ifthen' package failed.
This is pdfTeX, Version 3.14159265-2.6-1.40.21 (MiKTeX 21.1)
entering extended mode
[ERROR]   htlatex: Compilation errors in the htlatex run
[ERROR]   htlatex: Filename     Line    Message
[ERROR]   htlatex: ?    3        Package biblatex Error: Patching 'ifthen' package failed.
[STATUS]  make4ht: Conversion finished
========================

Looks like Miktex issue of some sort.

btw, better to use make4ht command to compile with.

--Nasser