bmake is used when building packages on a
NON NetBSD system. When building on a NetBSD system
make(1) is used. See
Using pkgsrc on non-netbsd systems.
The other thing that can cause you trouble is to mix repository binaries that were built with one version of pkgsrc with a different version of pkgsrc.
If you your goal is to get your first working NetBSD Desktop I would make several recommendations:
1) Use precompiled binaries (packages). Packages built with pkgsrc_2016Q3 have just finished several months of fixing build failures - it is as good as it's going to get.
2) Use amd64/i386.
3) I use NetBSD 7 but most builds are initiated with NetBSD 6.1 The 7.1 release candidate will have some teething problems and I would avoid it until you are comfortable with setting up a system from stable sources. Using a release candidate adds the extra variable of code in testing - did it fail because of something you did or is it just buggy?