After the change, I get the following on Hydra <https://hydra.gnu.org/build/3253608/log/raw>:

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@ build-started /gnu/store/scnqgfc3k4434h3gch22hnh0z8qdbvdb-disk-image.drv - x86_64-linux /var/log/guix/drvs/sc//nqgfc3k4434h3gch22hnh0z8qdbvdb-disk-image.drv.bz2
environment variable `PATH' set to `/gnu/store/5ka9gmcwcj2919q0cj0wkjng058lwrgq-qemu-minimal-3.0.0/bin:/gnu/store/5s2nib1lrd2101bbrivcl17kjx1mspw6-coreutils-8.30/bin'
creating raw image of 1024.00 MiB...
Formatting '/gnu/store/4yp6s4jlq2frb2jqzd7q3kp99vzmnpm5-disk-image', fmt=raw size=1073741824
Could not access KVM kernel module: Permission denied
qemu-system-x86_64: failed to initialize KVM: Permission denied
Backtrace:
           2 (primitive-load "/gnu/store/c2phacd8p7x3g8ysnzrx09jmnxp?")
In ./gnu/build/vm.scm:
    152:2  1 (load-in-linux-vm _ #:output _ #:qemu _ #:memory-size _ ?)
In ./guix/build/utils.scm:
    616:6  0 (invoke _ . _)

./guix/build/utils.scm:616:6: In procedure invoke:
Throw to key `srfi-34' with args `(#<condition &invoke-error [program: "qemu-system-x86_64" arguments: ("-nographic" "-no-reboot" "-m" "256" "-object" "rng-random,filename=/dev/urandom,id=guixsd-vm-rng" "-device" "virtio-rng-pci,rng=guixsd-vm-rng" "-virtfs" "local,id=store_dev,path=/gnu/store,security_model=none,mount_tag=store" "-virtfs" "local,id=xchg_dev,path=xchg,security_model=none,mount_tag=xchg" "-virtfs" "local,id=tmp_dev,path=tmp,security_model=none,mount_tag=tmp" "-kernel" "/gnu/store/fnpr2q7nwrqs7jb9dx7pd2v47z1g867v-linux-libre-4.19.7/bzImage" "-initrd" "/gnu/store/2rkg1w4v2c87ijk9mwba55whnq4v90dw-raw-initrd/initrd.cpio.gz" "-device" "virtio-blk,drive=myhd" "-drive" "if=none,file=/gnu/store/4yp6s4jlq2frb2jqzd7q3kp99vzmnpm5-disk-image,format=raw,id=myhd" "-enable-kvm" "-append" "panic=1 --load=/gnu/store/hqfz1xq82zgq5z1pm7bqisdr4xjsy95x-linux-vm-loader console=ttyS0" "-net" "nic,model=virtio") exit-status: 1 term-signal: #f stop-signal: #f] 5f6b00>)'.
builder for `/gnu/store/scnqgfc3k4434h3gch22hnh0z8qdbvdb-disk-image.drv' failed with exit code 1
@ build-failed /gnu/store/scnqgfc3k4434h3gch22hnh0z8qdbvdb-disk-image.drv - 1 builder for `/gnu/store/scnqgfc3k4434h3gch22hnh0z8qdbvdb-disk-image.drv' failed with exit code 1
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What does it mean?