The version 4.10 of samba is not defined as a value of SAMBA_DEFAULT variable in /usr/ports/Mk/Uses/samba.mk
If it was set in /etc/make.conf in DEFAULT_VERSIONS= samba=4.10 every port which depends on it doesn't build with the error "Invalid version of samba"
===> vlc-184.108.40.206,4 Invalid version of samba: 4.10.
*** Error code 1
Created attachment 205521 [details]
Patch to fix the problem
This was fixed r506035.
Date: Sat Jul 6 20:50:34 2019
New Revision: 506035
Add Samba 4.10 as a possible value for the DEFAULT_VERSIONS. 4.8 is still the default.