"Missing Signature" popup and warnings do not appear when installing package from tarball with a missing signature

Steps to reproduce:

1. Download the attached "com_unity.tarball.import-1.0.0.tgz"
2. Create a new URP project
3. Go to Window > Package Management > Package Manager
4. Click on the + button and select "Install package from tarball"
5. Select the previously downloaded .tgz
6. Observe the Package Manager

Actual results: No warnings appear and the "Missing Signature" popup is not shown

Expected results: "Missing Signature" popup appears and "Package 'com.unity.tarball.import' has been installed without a signature. For more details, check the Package Manager window (Window > Package Manager)." warning is shown in the Console

Reproducible with versions: 6000.3.0b6, 6000.3.15f1, 6000.4.6f1, 6000.5.0b7, 6000.6.0a4

Not reproducible with versions: 6000.3.0b5

 

Tested on (OS): Windows 11

Notes:

• Does not reproduce on macOS 26.4 and Ubuntu 24.04 - the popup and warnings are shown there