Comment 8 for bug 1898026

While a KeyboardInterrupt handler has been introduced to ubuntu-release-upgrader apt is actually sending the SIGINT back to the distribution upgrade process. This can be fixed in apt by removing the following:

--- apt-2.1.10ubuntu0.2/apt-pkg/contrib/fileutl.cc 2021-01-14 03:29:25.000000000 -0800
+++ apt-2.1.10ubuntu0.3~ppa1/apt-pkg/contrib/fileutl.cc 2021-02-26 09:13:10.000000000 -0800
@@ -140,10 +140,6 @@
       return _error->Errno("waitpid","Couldn't wait for subprocess");
    }

- // Restore sig int/quit
- signal(SIGQUIT,SIG_DFL);
- signal(SIGINT,SIG_DFL);
-
    // Check for an error code.
    if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
    {