macOS: "download & install" button on nightly does ~nothing

[antifuchs]

Describe the bug

When the nightly upgrade dialog pops up on my macOS 26 machine, it offers a "download & install" option; when clicking that, the button turns into "Downloading..." for a few seconds, and then turns back into "Download & install". I assume that it's running into an error, but none are reported that I can tell.

Reproduction

1. When the "Update Available" dialog pops up, click "Download & Install"
2. observe it becoming "Downloading..."
3. observe it becoming "Download & Install" with no message or evidence of work being done, after a few seconds.

Here's a screen recording:

Screen.Recording.2026-08-03.at.12.51.21.mov

Expected behavior

No response

Platform and versions

1. OS: macOS 26.6 (25G72)
2. nightly build
3. homeserver: continuwuity 0.5.10

Additional context

No response

[antifuchs]

Oops, seems like a dupe of #1471 (comment)