more about feature flags in macOS

it's been a minute. yes, i'm alive. i've just been neglecting this site (as i do with many responsibilities. oops!)

i wanted to touch on feature flags again. i've unearthed a few developments about them since my last post about them in june 2025, and i'll give a brief rundown.

the environment variable

starting around circa macOS 26, apple introduced a simpler method to control feature flags. this does not require reboots, and can be applied to apps individually. it is a simple environment variable. two, actually. FEATUREFLAGS_ENABLED and FEATUREFLAGS_DISABLED. these are simply applied at runtime via a shell. for example:

FEATUREFLAGS_DISABLED=SwiftUI/Solarium open /System/Applications/Music.app

this command disables solarium for the music app when launched. it does not affect other apps (though it may affect processes spawned from it.)

 

you can chain up multiple by separating them with a colon:

FEATUREFLAGS_DISABLED=SwiftUI/Solarium:AppKit/Glade open /System/Applications/Music.app

now obviously you cannot set glade anymore, but this is an example. beware that if you have one flag in FEATUREFLAGS_ENABLED and FEATUREFLAGS_DISABLED at the same time, you just receive a trace trap on launch.

the calistoga 

"what is calistoga?" you may ask. calistoga is the name for ANOTHER redesign of liquid glass, as seen in macOS/iOS/tvOS 27. previously, you could disable it by setting SwiftUI/Calistoga to false. macOS 27 beta 3 stripped this ability. perhaps because of my previous featureflag research (lol). it may still be possible to revert, but i'd need to look into the headers of SwiftUI and AppKit themselves, which i haven't gotten around to for macOS 27.

odd thing

logged in to post something today and saw this.

it looks somewhat like this.

at least from the editor, it looks like an inserted png. a pretty low-res one at that.

daily driving linux in 2025

it's been a while, but i haven't died—i promise. i've been drowning in school work for a while (by drowning, i mean procrastinating and then getting overwhelmed by my own doing...but that's neither here nor there)

back in about september 2025, i spilt soda on my macbook air and fried it. this began my journey of trying to use linux as my daily OS. so far, it's been successful. i don't game, so i don't have much issues using linux as an OS. so, let's get into what i'm using and why.

the setup

i use debian 13 trixie as my distro of choice, with KDE plasma 6.3.6 as the DE.

as you can see, i've somewhat themed it. it's not much, just the old oxygen theme from plasma 4. KDE still maintains it (which i'm thankful for, air was not so lucky) and i find it works rather well even on hiDPI minus the window decorations.

again, not a gamer. though KDE's inbuilt game selection has got me wasting a few minutes of time here and there playing solitaire or connecting wires in knetwalk. coming from a mac, the change is a bit jarring. but KDE is customizable, and at first i did.

initially i used this layout, a macOS-like layout to help ease me into the new desktop. it worked for a while, but rather quickly i gave it up and embraced the way KDE is set up by default. if it came that way, there must've been a good reason to. it took a bit of adjusting but i got used to it.

i find that KDE's battery life is great, especially in comparison to windows on the same machine—both 10 and 11. i can expect to hold a charge for 5-6 hours, sometimes 7 using KDE. windows would hold an astouding one to two hours before dying. and i wonder why i picked a mac 6 years ago.

i last used linux as a main OS in around 2020 or 2019. i can't remember specifically, but during that time, i used GNOME. naturally i came back to check in on what they were doing, and had quickly realized that GNOME had become an absolutely terrible looking DE. developers vehemently hate customization and GNOME itself had introduced a library called "libadwaita" to execute their ideology...and it doesn't even look good. so i stuck with my setup of KDE, of which i am very happy with. 

and why debian, you may ask? well, i am a long time iOS jailbreaker. never updating anything i have is in my blood. most other distros are "rolling release" where not updating every 5 picoseconds causes your device to brick, shit itself, and cause thermonuclear war. debian stable is, well, stable. each release has frozen packages where only security updates are pushed. you can, of course, add 3rd party repos and build software yourself if you need it...but the choice to not update is always there. and that's a good thing.

so yeah. for now, that's linux for me. 

disabling liquid glass on macOS 26 because it's a rushed piece of crap

are you a macOS beta tester? did you install macOS 26 on your main device even though literally everyone told you not to? well, congratulations, i've discovered a way to make you feel slightly better about your poor decisions.

simply un-Tahoe-ing macOS!

thanks to Apple Engineering™, we are able to simply disable the redesign (internally called "Solarium") and restore our mac almost completely 1-1 with how it was in sequoia.

to start, create the directory /Library/Preferences/FeatureFlags/Domain. save the following as SwiftUI.plist then FULLY REBOOT.

  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
  <dict>
      <key>Solarium</key>
      <dict>
          <key>Enabled</key>
          <false/>
      </dict>
  </dict>
  </plist>