Makefile.vm: Split error condition

[emaste]

Summary

Make it clear which of two possible cases applies.

PR: 295028

Test Plan

Minsoo can you apply this patch and test PR295028?

[minsoochoo0122_proton.me]

@emaste I get

make[7]: /usr/src/freebsd/main/release/Makefile.vm:105: NO_ROOT requires WITHOUT_QEMU
        in /usr/src/freebsd/main/release/Makefile:479
        in make[7] in directory "/usr/src/freebsd/main/release"

[minsoochoo0122_proton.me]

Not sure why this happens since I did make vm-image with sudo. I did buildworld and buildkernel with no root though.

[emaste]

I did buildworld and buildkernel with no root though.

If you're explicitly passing NO_ROOT to the build you have to add WITHOUT_QEMU as well

[minsoochoo0122_proton.me]

In D56837#1301961, @emaste wrote:

I did buildworld and buildkernel with no root though.

If you're explicitly passing NO_ROOT to the build you have to add WITHOUT_QEMU as well

For clarification, I didn't pass NO_ROOT=yes explicitly. I did buildworld and buildkernel without root privilege and I wonder if the build system automatically sets NO_ROOT to yes when it detects no root privilege?

[minsoochoo0122_proton.me]

Also, what is WITHOUT_QEMU exactly? It's not documented under src.conf(5).

[cperciva]

This should be going away at some point when WITHOUT_QEMU and NO_ROOT become unconditionally true, but this is certainly a useful change for now.

[emaste]

fwiw NO_ROOT is not in src.conf(5) either.

NO_ROOT means do not perform root-only operations during install (i.e., setting flags or ownership). WITHOUT_QEMU avoids using qemu for image building, using pkg's built-in METALOG writing infrastructure.