running emerge -uDN @world results in:

!! The following update has been skipped due to unsatisfied dependencies:
net-fs/samba:0

selected: net-fs/samba-4.8.2:0/0::net-kit, installed
skipped: net-fs/samba-4.8.3:0/0::net-kit, ebuild scheduled for merge (see unsatisfied dependency below)

emerge: there are no ebuilds to satisfy ">=sys-libs/ldb-1.3.4[ldap(+)?,python?,python_targets_python2_7(-)?,-python_single_target_jython2_7(-),-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),python_single_target_python2_7(+),abi_x86_32(-)?,abi_x86_64(-)?,abi_x86_x32(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?,abi_ppc_32(-)?,abi_ppc_64(-)?,abi_s390_32(-)?,abi_s390_64(-)?]".
(dependency required by "net-fs/samba-4.8.3::net-kit" [ebuild])

please update ldb from current version 1.3.3 to 1.3.4 to satisfy samba-4.8.3 dependency