> I thought the same thing but I set up arch on my main machine a couple of months ago and apart from the setup pain, it has been a much smaller hassle than I anticipated. It's pretty stable, didn't have any breakage until now. I love it!
As an Arch user of ~5-6 years, I do have some advice outside the obvious realm of "keep regular (working) backups" that can help minimize future headaches (not necessarily for you since you've likely already encountered these points; mostly for others who may be interested in dabbling with Arch):
1) Update often (at least once every 1-2 months; try not to let it get more than 6 months out of date), and keep a close eye on the news items--or, better yet, subscribe to the arch-announce mailing list. You'll get a heads up on anything that could be a potentially breaking change. When breaking changes come down the turnpike, don't panic--the Arch maintainers post upgrade instructions walking you through the process along with the appropriate news entry and it's usually fairly straightforward. There's also the forums if you get into a bind, and there's tons of great people willing to help (but search first!).
2) Keep your configurations up to date (either with `yaourt -C` or examining the .pacnew files by hand with vimdiff or similar). This isn't really Arch-specific, but because Arch is* a rolling release distribution, sometimes new versions of things come out fast enough that existing configurations can fall out of date and present unique challenges. But it all very much depends on the upgrade policy of upstream packages. Usually this isn't a problem unless.
Fortunately, the lion's share of "breaking" changes you'll encounter will be minor. The most recent one you've probably encountered by now may have been the certificate path issue with ca-certificates existing already. I suspect most of the major architectural changes are in the past at this point (mostly due to the disruption caused by systemd), but keeping your system relatively up to date is a great way to inoculate it against unnecessary future effort. It's always possible to upgrade ancient installs if you let them lapse (I should know!), but it's better to avoid that if possible.
I hope you continue to enjoy Arch for many years to come!
One concern I've had with Arch was how they would handle the big C/C++ library ABI changes. It only seems to happen about once a decade, but when it does it is a giant pain. Last time this happened while I was using Debian testing you had to pin a ton of packages for many months while everything moved over to the new ABI. How does Arch manage these core library ABI changes?
Arch is currently transitioning to GCC 7 and OpenSSL 1.1.0 (yes, both).
The GCC transition is a straight up replacement of packages, gcc and those built with the new gcc. Some AUR packages may need to be rebuilt, but the community of users agrees in some measure that that's something a user of AUR must know already.
The OpenSSL transition is keeping both versions around for a while, shunting the older version from package `openssl` to `openssl-1.0`, which will eventually go away too.
I guess the GCC 6 to 7 transition was not a big deal, but that could be partly because Arch tries to stick with upstream code and doesn't add patches of its own much.
> The OpenSSL transition is keeping both versions around for a while, shunting the older version from package `openssl` to `openssl-1.0`, which will eventually go away too.
In my experience, this hasn't been a terribly unsettling transition and has gone quite smoothly except for a few individuals unlucky enough to update during a mirror turnover (or so I gathered from the forums as their problems often went away after updating again a short time later).
Mostly, insofar as OpenSSL 1.1.x is concerned vs. openssl-1.0, I've only had problems with projects that make heavy use of cmake as there's no easy workaround outside either a) creating/linking a few directories that cmake expects to find OpenSSL 1.0 in, or b) (my preferred approach because it avoids polluting the file system) patching the FindOpenSSL macro. But, I don't think this is a problem Arch needs to resolve as this is most certainly an upstream issue and only affects AUR packages (which, as you said, users of the AUR should already have some experience in this area anyway!).
You're absolutely spot on with that last statement--one of the reasons I love Arch is because package maintainers keep things as close to upstream as possible and GCC updates have largely been painless. Certainly more so than I recall under Gentoo.
Now that I think about it, the few pain points I've encountered with less frequently updated Arch installations have almost always involved multiple incompatible changes to core/filesystem layered with pacman updates. There are others, sure, but those ones seem to stick out in my mind the most. It's better to avoid them entirely by updating regularly, of course, but it happens.
As an Arch user of ~5-6 years, I do have some advice outside the obvious realm of "keep regular (working) backups" that can help minimize future headaches (not necessarily for you since you've likely already encountered these points; mostly for others who may be interested in dabbling with Arch):
1) Update often (at least once every 1-2 months; try not to let it get more than 6 months out of date), and keep a close eye on the news items--or, better yet, subscribe to the arch-announce mailing list. You'll get a heads up on anything that could be a potentially breaking change. When breaking changes come down the turnpike, don't panic--the Arch maintainers post upgrade instructions walking you through the process along with the appropriate news entry and it's usually fairly straightforward. There's also the forums if you get into a bind, and there's tons of great people willing to help (but search first!).
2) Keep your configurations up to date (either with `yaourt -C` or examining the .pacnew files by hand with vimdiff or similar). This isn't really Arch-specific, but because Arch is* a rolling release distribution, sometimes new versions of things come out fast enough that existing configurations can fall out of date and present unique challenges. But it all very much depends on the upgrade policy of upstream packages. Usually this isn't a problem unless.
Fortunately, the lion's share of "breaking" changes you'll encounter will be minor. The most recent one you've probably encountered by now may have been the certificate path issue with ca-certificates existing already. I suspect most of the major architectural changes are in the past at this point (mostly due to the disruption caused by systemd), but keeping your system relatively up to date is a great way to inoculate it against unnecessary future effort. It's always possible to upgrade ancient installs if you let them lapse (I should know!), but it's better to avoid that if possible.
I hope you continue to enjoy Arch for many years to come!