Can you take a screenshot of this? What kind of models are you seeing this with? We don't see that in our environment. I know there was a special 19H4 installer build for some iMac model. But this is the first I'm seeing anything about 19H15.

I've seen this on both MacBooks and some iMacs... tho not many.

It does not show a 10.15.7 Build 19H15, but installianstallmacos.py does find a Build 19H4 that was released on 2020-10-27

@MagicMick Apparently there's a 19H15 Supplemental Update currently being tested. Are the Macs you're seeing that build on enrolled in AppleSeed?

@sdagley Nope. No AppleSeed.

I track every build of macOS and can not find a single speck of evidence of this build! If you could provide more Information, it would be helpful.

Will this do? I'm also trying to get a Screenshot of the About This Mac that shows the build number... So i'll report that here to...

@ClassicII Also, someone in the slack mac admin #catalina channel confirms that his macbook also updated to this new build...

@ClassicII Here you go!

I just got the pop-up about 10.15.7 Supplmental Update.
https://support.apple.com/en-us/HT211947

macOS will have the following build number after you install this update: 19H15

Yup we know for sure now!!!!

https://mrmacintosh.com/catalina-10-15-7-supplemental-update-19h15-released/

Everyone please provide your Apple contacts with how much you appreciate the lack of a 19H15 full installer. They managed to release a full installer of Build 19H4 last week that was solely for the 2017 21.5" iMac. Since 19H15 is intended for all Catalina capable Macs a full installer for it would certainly be more useful/appropriate.

We are starting to get it pushed out. I have a restriction policy to stop it but some devices get the policy and still have access to manually install the updates. Can figure it out.

@sdagley Right on. JAMF engineering please let Apple know on our behalf as well - it would save lots of admin work for Apple to produce full images for Supplemental and later Security Update builds... at the very least if they aren't available for download they are what should be delivered via internet recovery. It's silly in 2020 with super fast SSDs and NICs that we're strangled in volume deployments by Apple's premature murder of imaging, and then have to suffer these cuts and wounds of installing a base OS and then updating it immediate afterwards. What are we supporting here, Windows 95? At least MS provided a way to slipstream updates for admins. I've tried those package installation switches ( startosinstall --installpackage ) and it produces unbootable systems for Security Updates. I know, this is not strictly a JAMF issue and imaging is dead but the amount of labor hours lost esp when you're deploying systems for developers and want to include things like xcode or heaven forbid MS Office which still unpacks itself to /tmp and then uses ditto to move its components into /Applications... It makes me long to manage modern Windows!

@jschank Today I could download the full macOS Catalina installer 19H15 from MDS, I have not tried installing yet.
Cheers
Carlo

Apple released a full installer for 10.15.7 Build 19H14 yesterday. You can also use installinstallmacos.py or erase-install (which itself uses installinstallmacos.py, but adds a few options) to download it. I've found those to be somewhat more reliable than the softwareupdate --fetch-full-installer --full-installer-version 10.15.7 (if you're on a Mac already running Catalina)

Apple just updated Catalina installer in App Store, comes by version 15.7.03