How to install macOS Tahoe 26 on an external drive

I thought I had found a solution with the official virtualization framework (I use the app virtualOS on the App Store). But there seems to be a bug in the virtualization framework that prevents creating macOS 27 VMs. Can Apple provide any official steps on how to install macOS 27 without spending thousands on dollars on new hardware?

On the virtualisation front, Apple doesn’t have a virtualisation product per se. Rather, we provide the Virtualization framework which allows developers to create products. You’ve already found the thread where we’ve been discussing the current installation issues that’s affecting those developers. If you’re looking for advice for specific product, I recommend that you connect with the support resources for that product.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

I wasn't looking for advice for a specific product. I was just wondering since installing macOS on a separate partition doesn't work, and the Virtualization framework currently doesn't work either... what's the official way of installing macOS 27? Are we really supposed to have dedicated hardware for that, separate from our working machines?

the Virtualization framework currently doesn't work either

I disagree with you here, because I’m literally running macOS 27 beta in a VM while I type this [1]. And just to be clear, I’m using all public hardware and software [2], including a third-party VM app (VirtualBuddy).

The bugs discussed on that other thread are annoying, but they’re not showstoppers.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

[1] Now, admittedly, it’s 27.0b1, not 27.0b3, but that’s just because I’ve not had a chance to upgrade it.

[2] By which I mean “released to non-Apple folks”. Specifically, my host is macOS 26.5.2 running on a production MacBook Pro.

How you created that VM is what I'd like to have confirmed. Should I use this VirtualBuddy app? Is that app actually enough? In the link I read that one needs to actually create the VM on a macOS 27 host, but again, I haven't been able to install macOS on separate partitions in the past years, and installing it on separate hardware is out of the question for me.

How you created that VM is what I'd like to have confirmed._

I’d post steps but I’ve actually forgotten )-: It was early in the macOS 27 beta cycle, and I’d definitely installed Xcode 27 beta before attempting this, so I had to jump through some hoops. I think they involved a prerelease of VB and a setting some magic user default, but I didn’t note down the details at the time, and I don’t have time to try it again today.

And hence my original reply here, recommending that you research this via the support resources for the specific virtualisation solution you’re using.

I will eventually find time to get back to this, but it’s possible that macOS 26.6 will be released before that (it’s currently an RC) which should smooth this path considerably.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

See? That's what I meant. Already the mention of an unspecified "magic user default" tells me that I shouldn't bother messing with this. If even an Apple employee doesn't have the time or energy to share the necessary steps that anyone could follow without having to do "research", imagine how willing a third-party developer must be. The cumulative millions of hours spent globally to figure this out, each one on their own...

I would be happy to test if issues are fixed. Right now I feel like Apple doesn't value my time.

Already the mention of an unspecified "magic user default" tells me that I shouldn't bother messing with this.

To be clear, that’s not an Apple user default, but a VirtualBuddy one.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"