v0.2.5

Fixed

• /dev/kvm existed and could not be opened. The node is there on a
  GitHub runner — the job checks it first, and kvm-ok agrees — but it belongs
  to the kvm group, and the runner account is not in it. QEMU then fails
  with Qemu failed to start, a message that names neither the file nor the
  right, and Packer halts twenty-three seconds in. A udev rule now makes the
  node accessible, and the job opens it rather than assuming the rule
  worked: a check that cannot look never concludes green.

• The build is no longer silent about its own failure. PACKER_LOG=1 now
  writes to a file, and the last two hundred lines are printed only when the
  build fails. The verbose log is unreadable when everything works and
  indispensable when QEMU says nothing useful — which is exactly the situation
  that cost this release.