https://issues.redhat.com/browse/RHEL-92239
After this, output looks like
$ ./run guestfish --ro --format=qcow2 -a test.img
libguestfs: error: qemu-img: qemu-img: /home/crobinso/src/libguestfs/tmp/libguestfsFlxnb0/overlay1.qcow2: Image is not in qcow2 format Could not open backing image. : qemu-img exited with error status 1.
To see full error messages you may need to enable debugging.
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Signed-off-by: Cole Robinson <crobinso@redhat.com>