I've compiled all of Halfquake Amen and noticed a few minor things which I can fix easily. Most maps have "unused values" after switching to Spirit, and also most of those can be fixed with the press of a button.
There were some compiling errors I think, but I'll find out as soon as I play through all of it.
Last week there was a live stream of HQA and I noted down some things that I may or may not want to fix. I've gone through them and I'm planning on posting them on my github project as issues.
I've had an interesting discussion with Dave: Half-Life on Steam works for Mac and Linux (it has worked on those platforms for a while I think), and he told me that he got all three Halfquake parts running there as well by adding the missing .so and .dylib files. The problem is that those files work well with regular Half-Life, but Halfquake Sunrise uses Spirit of Half-Life and it has some weird side effects, like sound starting again after reloading and other errors.
I'm not sure that I can fix these issues, so the HQ Trilogy will most definitely remain a Windows-only game. I guess it's not that big of a deal, but still worth mentioning I think.
(Note: Cry of Fear is also Windows-only, and I know how hard these guys worked to make the standalone version.)
Next on my list is to play through everything I have right now and note down everything I need to fix. So far, the first few maps of HQA look very promising, even the intro camera worked right away (unlike the camera of HQ1). Wish me luck for the rest!