The sys-apps/shadow ebuild (current is 4.0.3-r8) supports PAM-less install. There is a line in the ebuild that would install login.defs into /etc except that it is commented out because that file is provided by pam-login. This line should be executed if pam is not being used. Attached is my login.defs (tweaked from the defaults to be more gentoo) that should be modified if necessary, and then dumped in sys-app/shadow file directory. Reproducible: Always Steps to Reproduce:
Created attachment 21908 [details] login.defs for sys-app/shadow files directory
Created attachment 21909 [details] login.defs for sys-app/shadow files directory (fixed)
4.0.5 now supports USE=-pam properly
Unfortunately now I have problem with USE=-pam (described in Bug 69864)
unrelated problem