CHM build issues

Attempted to build the CHM (non-enhanced) version of the manual and while the build itself appears to work, I ran into issues compiling the output into a chm file.

There's some CHM build instructions at https://github.com/php/phd/blob/master/phpdotnet/phd/Package/PHP/HOWTO.GENERATE_CHM but as you'll see from my notes below, they're not very helpful.

The first issue I encountered is that HTMLHelp Workshop (which contains the HTMLHelp Compiler) will not install on Windows 11 (installer errors saying a newer version is already installed).

Additionally I should note HTMLHelp Workshop no longer appears to be available for download from Microsoft (there's web documentation for it, but none of the download links leads anywhere. The closest I could find was this MS Answers post linking to an archive.org copy

I then tried the chmcmd compiler from freepascal on Linux (I was using fpc 3.2.2 on Gentoo). While this appeared to create a .chm file, this file failed to load on Windows 11. Additionally it output an Access Violation error.

chmcmd produced a number of warnings relating to content during the build. The most common 2 were:

• Warning: Found file res/language.types.value.html while scanning res/<filename>.html, but couldn't find it on disk - appears to be caused by specific instances of the <type> tag on true and false
• Warning: Found file res/ while scanning res/mongodb.persistence.html, but couldn't find it on disk - appears to be caused by anchors with no file attached. I think created by (for example) <footnoteref linkend="mongodb.pclass"/>

Does anyone have working instructions / tools to build the chm version of the manual?

The apparent lack of tools for building CHMs (I did have a search but there weren't many options, never mind free and maintained options) has me moving towards suggesting dropping support for CHM.

Start with phpdotnet/phd/Package/PHP/HOWTO.GENERATE_CHM and review the reported HTMLHelp Workshop and Free Pascal chmcmd failures. Reproduce the CHM build if possible, including the missing-file warnings and Windows loading failure. Done means documented working tools and steps, or a clear basis for dropping CHM support.