Since we have to build *sys-libs/libcap* with the default Portage
configuration in order to avoid the circular dependency with PAM,
our configuration for binary package builds is not yet in place. We
need to explicitly specify where to put the built packages and enable
multi-instance packages.
Several packages end up with circular dependencies, depending on which
Portage profile is selected. The default profiles have a circular
dependency between *sys-libs/pam* and *sys-libs/libcap*. Systemd and
SELinux profiles have even more issues.
We can break the circular dependencies by explicitly building *libcap*
with`USE=-pam` first, which happens to be the default configuration
generated by `crossdev`. Then, we need to switch to a more complete
profile in order to build *glibc* and *util-linux*. At this point, the
build root should be complete enough to build anything without circular
dependencies.
Dustin