[Qubes-Builder] RPM Permisions issues in linux-template-builder

Building Qubes ISO via release 4.1 following the tutorial at:

First, I am running into an issue when building Qubes via qubes-builder on Fedora33. Once reaching the build of template fedora-30/fc30, the following error resides:
Building template: fedora-30
→ Preparing instalation of fc30 template…
→ Image file already exists, assuming update
→ Initializing RPM database…
error: can’t create transaction lock on /home/cogent/qubes-builder/qubes-src/linux-template-builder/mnt/var/lib/rpm/.rpm.lock (Permission denied)

Upon viewing the qubes-src/linux-template-builder I noticed ./mnt is owned by root (not sure if this is by design).

Is this something I have done wrong? The Fedora33 build I am using is fresh and only used to build Qubes.

Secondly, is there a way to re-run the build/make from the previous failure rather than rebuilding everything from scratch for when there is an error such as this one?

Any help is much appreciated