The single file launcher for both scummvm variants (native/libretro) can be achieved like this:

Make a folder with the ScummVM Game Id with the extension, thus sword1.svm in the roms/scummvm/ folder. Put the gamefiles into that folder, and add no *.svm in here Run scummvm from ES, select Add Game in ScummVM, select the folder sword1.svm you just created Remember / note the gameid provided by ScummVM autodetection (maybe sword1-win-gb, e.g containing some variants information)

Now, if the game id from autodetect is different than your created game id folder, there are two options to rectify the situation:

Either edit the scummvm.ini (in /opt/retropie/configs/scummvm) and change the ini section name from [sword1-win-gb] to [sword1]

Or rename the game folder from sword1.svm/ to sword1-win-gb/ in the filesystem.

You may encounter files (not directories) with the extension *.svm directly below the roms/scummvm/ folder. These are caused by the lines in +Start ScummVM.sh:

while read id desc; do echo "$desc" > "/home/pi/RetroPie/roms/scummvm/$id.svm" done < <(/opt/retropie/emulators/scummvm/bin/scummvm --list-targets | tail -n +3)

Disable/remove them to avoid having these re-appear after each ScummVM run.
Remove also the files *.svm with find $HOME/RetroPie/roms/scummvm/ -name "*.svm" -type f -exec rm -f {}

Important: Key is to have the game id folder name match the entry in the scummvm.ini for the native ScummVM the game id derived from the folder is passed to ScummVM.

In contrast lr-scummvm does not rely on *.svm files/folders at all. (Technical details: When launching lr-scummvm the absolute path of the game is passed to the libretro core. The core then searches for a *.scummvm (sic!) file with the game id in that path, if that is not found it falls back to autodetection.)

With this setup Skyscraper will detect and scrape the games properly.

Epilogue:
Also keep in mind that ScummVM and lr-scummvm are using scummvm.ini files in different locations.

ScummVM: /opt/retropie/configs/scummvm
lr-scummvm: $HOME/RetroPie/BIOS/scummvm

This setup works but may be a awkward (imposing file/foldernames, many manual steps in the right order, possibility of diversion of scummvm.ini files). Thus I came up with a more user-friendly approach, you may read the gory details in this thread

@Lolonois Thank you!

@sleve_mcdichael said in stop ScummVM from generating .svm files?:

If you run the command manually, does your output look like mine?

nope, there's an additional line: Using configuration file: /opt/...

using tail -n +4 solves that then. Sorry for bothering you with this, seems like something I could've figured out...

You can try scraping them. That's what the <platform> tag is for in es_systems.cfg, where you configured the custom system.

looks like I'd removed that line (in my attempts to isolate from the main scummvm), but I'm adding it back in now.
(even though not all games there are scummvm...)

i've used skyscraper before, thanks for the tips!

Was there a reason you want to use the scummvm.ini contents, specifically?

oh, no, it just looked like there's more info in there, but not much of it is useful for scraping anyway

thanks for everything, i think i can handle it from here :)

Thanks for replying with the workaround you found.
And yes, the implementation and wiki are not aligned yet as there is a pull request pending.

If you stick to ScummVM only (and not plan to use retroarch / lr-scummvm) these suggested changes work well, as they do interchange filename and filecontent.

However, when lr-scummvm is considered to use the same setup things get a little more wicked, I assume this is why there is no decision yet which way to implement it.

@windg well, the ScummVM RP documentation is not aligned with the implementation. And it will create a clutter in the scummvm/ folder, plus will rewrite the *.svm files everytime after exiting ScummVM, which is surplus.

This and the missing interop with the LR variant made me to have a design which creates a more "it just works" experience for the user.