In a rare move, Cydia creator Saurik has updated Cydia Substrate “to support iOS 13.” The update also fixes a “serious resource leak that would eventually cause Substrate to lock up and break.”
The latest release of Cydia Substrate carries the version number 0.9.7100. Cydia Substrate is used for tweak injection in Unc0ver and checkra1n jailbreak, the latter being used for jailbreaking iOS 13 – iOS 13.3 running on iPhone 5s to iPhone X.
If you have an iPhone or iPad running iOS 13 – iOS 13.3 that’s jailbroken, you should definitely update to the latest version of Cydia Substrate due to the major resource leak it fixes. If you faced issues with jailbreak tweaks after a few hours of use of booting up/restarting your phone, this update should fix the issue. Below is how Checkra1n and Unc0ver co-developer Sam Bingner explains the update:
Saurik has updated mobilesubstrate to fix the issue where it would stop hooking after an indeterminate period. It was found to be due to a mach port name leak that would cause it to no longer be able to modify processes after spawning somewhere around 50,000 processes. I’ve tested it with a few hundred thousand processes and it’s been clean. The version number is now non-beta as the known issues of stability and cynject have been fixed. The update is on elucubratus if you’re using a non-A12 device.
The update should show up when you open the Cydia app. If not, simply refresh the sources and the update should be available.
You can jailbreak older iPhones until the iPhone X running iOS 13 – iOS 13.3 using the checkra1n jailbreak tool.