I ran sudo do-release-upgrade -d to switch to the development release in a VM, hopefully to contribute to Ubuntu, and got the following message:
Foreign Packages Installed
The following unofficial packages are currently installed:
gir1.2-javascriptcoregtk-4.1Installed from: unknown origin
gir1.2-webkit2-4.1.......Installed from: unknown origin
libjavascriptcoregtk-4.1-0Installed from: unknown origin
libjavascriptcoregtk-6.0-1Installed from: unknown origin
libwebkit2gtk-4.1-0......Installed from: unknown origin
libwebkitgtk-6.0-4.......Installed from: unknown origin
It is recommended to install supported versions from the Ubuntu
archive, and try the upgrade again.
Do you want to continue the upgrade anyways?
Continue [yN]
Why do I have “Foreign Packages Installed”? And how can I “install supported versions from the Ubuntu archive”?
$ apt list --installed gir1.2-webkit2-4.1
gir1.2-webkit2-4.1/plucky-updates,plucky-security,now 2.48.5-0ubuntu0.25.04.1 arm64 [installed,automatic]
Notice: There is 1 additional version. Please use the '-a' switch to see it