Archive for November 18, 2021

Thursday, November 18, 2021

Forgotten Image Formats

Ernie Smith (via Gus Mueller, Hacker News):

Around this time 30 years ago, two separate working groups were putting the finishing touches on technical standards that would come to reshape the way people observed the world. One technical standard reshaped the way that people used an important piece of office equipment at the time: the fax machine. The other would basically reshape just about everything else, becoming the de facto way that high-quality images and low-quality memes alike are shared on the internet and in professional settings. They took two divergent paths, but they came from the same place: The world of compression standards. The average person has no idea what JBIG, the compression standard most fax machines use, is—but they’ve most assuredly heard about JPEG, which was first publicly released in 1992. The JPEG format is awesome and culture-defining, but this is Tedium, and I am of course more interested in the no-name formats of the world.

Are TIFF, BMP, and PCX really considered to be forgotten?


Bartosz Polaczyk (Hacker News):

We are excited to be open sourcing XCRemoteCache, the library we created to mitigate long local builds. As the name suggests, this library is a remote caching implementation for iOS projects with an aim to reuse Xcode target artifacts generated on Continuous Integration (CI) machines. It supports Objective-C, Swift, and ObjC+Swift targets and can be easily integrated with existing Xcode projects, including ones managed by CocoaPods or Carthage.


A remote cache is a popular technique to speed up builds of big applications by applying the “compile once, use everywhere” approach. As long as all input files and compilation parameters are the same, instead of building a target locally, one can download artifacts that were built and shared from some other machine. A key success factor for remote caching is finding an optimal caching level. Caching units that are too granular, where every single piece of the compilation step is cacheable, may lead to extensive network traffic overhead, which can offset CPU savings. On the other hand, putting the entire codebase into a single cacheable unit may significantly degrade the caching hit rate; every single local change invalidates remotely available cache artifacts, triggering a full build, locally.

The main Spotify iOS application is highly modularized and contains more than 400 independent modules configured as separate Xcode targets. Applying target-level caching was natural, and as we found out later, the right decision.


WebKit E-mail Formatting Bug

Adam Engst:

Now and then, we get a report from a reader whose TidBITS issue has an entire article formatted as a column of text that’s a single character wide. I could tell what happened in at least two cases, but I’m utterly stumped as to what might be causing it. The problem doesn’t appear to originate on our end.

In one report where the reader forwarded the badly formatted issue to us, the problem stemmed from CSS corruption.

I’m not sure what causes this, but I’ve seen it happen to a variety of e-mails (though none from TidBITS) starting with Catalina, both in Mail itself and in my app that uses WebKit to render HTML e-mails. For me, at least, it’s a transitory problem that goes away if I relaunch the app and view the same e-mail again.

See also: Peter Steinberger.

Pacifist 4.0.1

Filipe Espósito:

Pacifist is a popular file extractor for macOS that lets users view and extract multiple file formats, including PKG, DMG, XAR, and TAR.


Completely rewritten in Swift 5


Added command-line interface


Support for Asset Catalog files

Support for Mac OS 9 Installation Tome files

It’s $20 or $10 to upgrade.


How to Use Apple’s Legacy Contact Feature

Juli Clover:

Apple in iOS 15.2 is making it easier for your loved ones to access your personal data in the event of your death with the addition of a Legacy Contact feature. A person set as your Legacy Contact gets a special code that can be provided to Apple alongside a death certificate to unlock your device.

The Legacy Contact that you set will have access to your Messages, photos, notes, and other sensitive data, plus the ability to remove Activation Lock from your devices, so it is an opt-in feature and should be reserved for your most trusted contact. This how to walks you through how to enable Legacy Contacts, covers how to get to the data after a death, and outlines some of the data that will be accessible.

On macOS 12.1 Beta 3, I see a way to add a Recovery Contact in System Preferences but not how to add a Legacy Contact.