This is partly a general GOG on Linux question currently not addressed in the support faq, but since there can be game specific issues and it's currently relevant to KSP, I thought I'd raise the question here.

Anecdotal it-works-for-me feedback is welcome, but I'd like to see the offical GOG perspective as well. So on to the question:

At present, the updated KSP downloads for Linux are only in the form of the full installer rather than patches.

What I did for the 1.0.5 update and the subsequent bug fix (after backing up the game directory) is uninstall the game using the "uninstall Kerbal Space Program.sh" script, then installing the game again from scratch using the updated installer.

This seems to work ok and preserves settings and game progress, but is still a little worrisome because it may not always be true that everything will carry over to a reinstall properly and I don't really want to waste time mucking about figuring out what to copy from my backup. It would be preferable if running the new installer just updated everything properly, but I have no basis for thinking the installer is designed to do in-place updates.

What's the recommended GOG way of updating an installed game on Linux in the absence of a patch, and what do my fellow KSPers do?

Uninstall + reinstall should always work fine, games complaint with Free Desktop guidelines should always put configuration and save games in $HOME/.config and/or $HOME/.local, never in the game install directory (typically if you've multiple users on the computer, you should be able to install it only once, and each user would have his own settings and progression).

- install KSP into a new folder
- copy savegames and settings from old version to new folder
- delete older folder
- go to forums to check if I can copy the mods as well or if they need an update yeah, that doesn't work with KSP :)

It turns out for KSP the uninstall leaves files behind in the KSP folder, which includes settings and save games (I'm guessing anything that isn't explicitly listed in the uninstall configuration). A re-install using the default settings (~/GOG Games) will install into the still existing game folder and settings/saves are picked up by the new version. (Except save games are useless since 1.0.5 requires a new game for science or career mode, LOL)

So now we have 3 similar methods (so far) that seem to work for this game, which nicely illustrates my point. That's why I specifically stipulated the "GOG recommended" way. If there is an as yet undocumented upgrade process designed into the installer/uninstaller, I would like to know about it. If it's undocumented, it should be in the FAQ. That way, if things aren't working as intended, they can be reported and fixed.

If there's no design beyond rudimentary install/uninstall, that's unfortunate and probably needs to change, otherwise Galaxy on Linux will be all kinds of painful. Based on how the Windows version of Galaxy behaves, a managed upgrade path seems to be a necessity. I don't see how that can happen easily without a fairly robust install/uninstall/backup/upgrade/rollback process in place beforehand.

I'm very grateful for the Linux support, and happy that it's come along so nicely, particularly the installer. I'd like to help make it better. It seemed like identifying and discussing shortcomings so they can be improved was a good way to start. And here we are.

ok, good to know that it works.
i was just thinking about how KSP stores everything in its game folder, not in $HOME/.config or whatever as mentioned above. might be worth asking either Support or in the General forum, since the question isn't really KSP specific. And the game forums usually don't see that much visitors :).

Thanks for the response.

Based on reading how the 1.0.4 -> 1.0.5 transition went for most people, I don't see how that would work without issues. This wasn't a simple bugfix upgrade as is common with many (most?) commercial games. This update changed enough core game functionality that moving the old game out of the way as a backup, or installing the new release into a versioned directory (eg. Gog Games/Kerbal Space Program 1.0.5) would make more sense.

:-) You must not be a KSP player.

"Issues" may be the wrong word. To use a Linux analogy, the update was more like a major new version of a distribution than a minor increment with some security updates, bug fixes and tweaks. This was a pretty major change with some significant consequences. The secondary release was to fix issues in the traditional sense, as you indicate.

I think long-time KSP players (I'm not one of them) that have been with the game as it evolved are used to this. It seems to be part of the culture in fact, and significant changes in the game are welcomed with delight since it's just another thing to learn and figure out as you explore your way through the game. So not necessarily a bad thing. But maybe an unwelcome surprise to the unaware GOGer that sees an update and applies it (or has it applied automatically by Galaxy).

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Some of the 'issues' were:

Many mods didn't work any longer, or didn't quite work right. Fixes and updates are being/have been issued but that takes time.

Several spaceship/aircraft parts were updated and/or moved to a different place in the parts tree. So parts that were unlocked and available in an ongoing science or career based game were no longer unlocked in the new game.
Continuing an ongoing game wasn't always possible because your existing craft wouldn't work right, or parts they needed weren't available since they weren't yet 'unlocked' in the new version.

Since I wasn't that far along in the game, my response was to just start over again from the beginning. That seemed to be the general approach taken by most. Many people seemed to keep a copy of the older version around to play in parallel with the new one until they finished migrating stuff over, their favorite mods caught up etc.

I hear ya. 20 years this month since my first linux install, so my survival skills are strong. I ask stuff like this not because I don't know what to do, but because I'm lazy and want things to be better and easier. 20 years of suffering is enough. :-)

blatant lies.

Here I am downloading 30gb for a 1.01 -> 1.02 patch?