现在，每当我使用 vagrant 时，它都会尝试libvirt用作提供程序。我想默认使用 VirtualBox。
vagrant-libvirt 未安装。
这很麻烦，因为有些命令不起作用，例如vagrant status：
[florian@localhost local]$ vagrant status
The provider 'libvirt' could not be found, but was requested to
back the machine 'foobar'. Please use a provider that exists.
[florian@localhost local]$ vagrant status --provider=virtualbox
An invalid option was specified. The help for this command
is available below.
Usage: vagrant status [name]
-h, --help Print this help
在 Debian 上，运行时：
$ fakeroot cdebootstrap stable /tmp/foo
cdebootstrap 下载软件包，但是当它必须解压它们时，我收到此错误：
E: Failed to unshare: Operation not permitted
如何以非 root 身份运行 cdebootstrap？
取消共享手册中的这一部分似乎相关，但我不确定如何：
EPERM (since Linux 3.9)
CLONE_NEWUSER was specified in flags and the caller is in a
chroot environment (i.e., the caller's root directory does not
match the root directory of the mount namespace in which it
resides).