From @mes on Discord:

I'm having trouble with virtualbox. The 7.0.2 ebuild is broken many ways. First the virtualbox ebuild has a +chm IUSE, but virtualbox-bin requires kchmviewer to finish the install but there is no DEPEND requiring that package. I don't know why chm is required the package builds fine without it.

Unfortunately it will not start the VBox manager since it needs libgssapi_krb5.so.2 to run. adding app-crypt/mit-krb5 fixes that but again not in the RDEPENDS.