bug#50681: pinebook-pro-barebones-raw-image is not reproducible

[Martin]

Hello,
I've noticed that you are producing an image for arm64 pinebook pro 
machine http://guix.gnu.org/en/download/latest/ so I've decided to test 
it on my x86 PC:
---
  guix 173b4e4
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 173b4e453cf24b21dffafbfd21b9e3007ae215a6
---

The following command: guix system image 
https://raw.githubusercontent.com/guix-mirror/guix/da4e40948326387d5bcda58783914d5f9ce8b095/gnu/system/images/pinebook-pro.scm 


...is producing the desired image 
/gnu/store/sb961183rlm0j7hl0c77z1cxb01m0vyi-pinebook-pro-barebones-raw-image 
but with different checksums each time I'm trying to reproduce it in my 
fixed environment.

Any ideas how to fix it?


Kind regards!
Martin