bug reporting - How do I report a bug that happens during boot?

I seem to have found a bug in 12.04 while it's booting, but all the questions on this site seem to point users to reporting bugs once the desktop is up and running by using ubuntu-bug.

How do I report a bug where I can't use ubuntu-bug and where I don't know the package name?

According to the finding the right package page:

During boot If you encounter a bug with the boot splash screen
(typically an Ubuntu logo displayed during boot), the package is:

plymouth since 10.04 Lucid Lynx If the screen goes blank after the
splash screen (about the time the login screen should come up), report
the bug against xorg.

If the boot errors or freezes even in "recovery mode", the bug should
be reported against the kernel.

See also:

for more things you can add to the bug report.