vagrant: don't use `qemu_use_session`.

centos-ci complains about it and fails.
fedora needs it though.
As a workaround, out this into ~/.vagrant.d/Vagrantfile:

```
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.qemu_use_session = false
  end
end
```

Signed-off-by: Michael Adam <obnox@samba.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/vagrant/Vagrantfile b/vagrant/Vagrantfile
index 23ebc45..57bc6ac 100644
--- a/vagrant/Vagrantfile
+++ b/vagrant/Vagrantfile
@@ -14,7 +14,20 @@ Vagrant.configure("2") do |config|
     config.vm.provider :libvirt do |v,override|
         override.vm.box = "centos/7"
         override.vm.synced_folder '.', '/vagrant', disabled: true
-        v.qemu_use_session = false
+
+        # We can not use qemu_use_session universally.
+        # - On Fedora 31, it is required for me to start.
+        # - But on centos7, it must not be set.
+        # The best workarount I found is to put this setting into
+        # your ~/.vagrant.d/Vagrantfile like so:
+        # ```
+        # Vagrant.configure("2") do |config|
+        #   config.vm.provider :libvirt do |libvirt|
+        #     libvirt.qemu_use_session = false
+        #   end
+        # end
+        # ```
+        #v.qemu_use_session = false
     end
 
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