It seems like a lot of GOG games now only offer installers that include Galaxy. lgogdownloader seems not to download these at all. Is there a way to get these with lgogdownloader, maybe using the Galaxy API? And maybe prefer non-Galaxy installers if they are available?

You should be able to find non galaxy installers by clicking More and selecting Classic Installers. If there is any game that doesn't have classic installers, please do send a support ticket about it.
Galaxy also only downloads classic installers btw.

Thanks, I didn't know about the link under More.

So, it looks like the problem is that lgogdownloader is not downloading any installer when a Galaxy installer exists.

I am using LGOGDownloader 3.2.6c2a3b4 and calling it as
lgogdownloader --download --platform l,w

Don't be specific and mention the games with the problem, but it's likely this issue.
No idea if it would help, but you could try an older build (pre 706158d).

I submitted a report to GOG support alongside a list of games where the GOG Galaxy Client Backup feature fizzles out and lgogdownloader does not include the installer in the product files listing.

Currently, there are 92 games out of 1250 of my games (DLC excluded) where this problem arises, for a full listing, see https://github.com/Sude-/lgogdownloader/issues/125#issuecomment-334993812 (lgogdownloaders bug report discussion).

I included a small script to check for yourself which games are affected, I don't own every game here.

It looks like this has been fixed. At least I do not get reports for missing installers, other than for xenonauts_2_demo, which always has been available exclusively through Galaxy only.

The fix introduced a minor change in the API which caused lgogdownloader to not get valid file names.
79aa66a fixes the file name issue.

On a second thought, could it be that I am not affected by this problem because I still use the last version of lgogdownloader before switching to the Galaxy API (6f42fec)?

Is there any difference or advantage in using the Galaxy API or is it because GOG's non-Galaxy API will be switched off at some point?

There isn't much difference other than that --download-file doesn't work with Galaxy API at the moment but I'll see if I can also migrate that feature to Galaxy API in future.
My main reason for switching the downloader to Galaxy API was because the old API had some issues earlier.
Also the fact that the old API can be switched off any time was a major reason for switching to Galaxy API.

Yet another change to url formatting in "downlink" json response.
This time I knew it was coming thanks to my discussion with GOG support so I was prepared to fix any issues it would cause to lgogdownloader.
The reason for the change was issues that the previous formatting caused to Galaxy: https://www.gog.com/forum/general/gog_galaxy_bug_1/page1
It was easier/faster for GOG to change the url formatting in API response than to release a patch for Galaxy.

eee1621 Galaxy: Fix getting file name (again)

I can confirm this, after another (lengthy) scan, no games had missing installer files; guess my ticket helped :)

When I switch to a version which uses the Galaxy API I get a runtime error when I try to update my cache (lgogdownloader-v3.2-25-geee1621 --update-cache): The error already has been introduced with commit 706158d and is still present in the current version. It happens in the second phase when lgogdownloader retrieves the game infos, around the 4th or 5th game, but at different places with each lgogdownloader run. The last actions before lgogdownloader aborts mostly look like this: Not sure if that helps at all...

I would be interested in backtrace from debug build

mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Debug
make
gdb ./lgogdownloader
run --update-cache

after the downloader crashes type
thread apply all bt

[long log removed]

That's weird. I don't see anything about string conversion in there.
Maybe I'm missing something obvious.

Try the same with 1 thread
gdb ./lgogdownloader
run --update-cache --threads 1