I built a CentOS 8 environment with Vagrant and tried to sync_folder, but I got an error, so I solved it.

Errors and solutions that occur with sync_folder

When I tried to develop a system using CodeIgniter of php by specifying sync_folder in the definition of Vagrantfile, I got an error.

Below is the definition of Vagrantfile.

Vagrantfile

Vagrant.configure("2") do |config|
  config.vm.box = "centos/8"
  config.vm.network "private_network", ip: "192.168.33.10"
  config.vm.provider "virtualbox" do |vb|
    vb.customize ["modifyvm", :id, "--memory", "2048"]
  end
  config.vm.provision :shell, :path => "./provision.sh", :privileged => true

  config.vm.synced_folder "./codeigniter", "/var/www/html/codeigniter"
end

When I vagrant up, I got the following error in red letters near the end.

Error with vagrant up

The following SSH command responded with a non-zero exit status.
Vagrant assumes that this means the command failed!

/usr/sbin/rcvboxadd setup

Stdout from the command:

VirtualBox Guest Additions: Starting.
VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel 
modules.  This may take a while.
VirtualBox Guest Additions: To build modules for other installed kernels, run
VirtualBox Guest Additions:   /sbin/rcvboxadd quicksetup <version>
VirtualBox Guest Additions: or
VirtualBox Guest Additions:   /sbin/rcvboxadd quicksetup all
VirtualBox Guest Additions: Building the modules for kernel 
4.18.0-193.19.1.el8_2.x86_64.

VirtualBox Guest Additions: Look at /var/log/vboxadd-setup.log to find out what 
went wrong


Stderr from the command:

modprobe vboxguest failed
The log file /var/log/vboxadd-setup.log may contain further information.

Take a look at the contents of the /var/log/vboxadd-setup.log file as this error message points out. Access CentOS started with vagrant ssh and check the log.

less /var/log/vboxadd-setup.log

Building the main Guest Additions 6.1.12 module for kernel 4.18.0-193.19.1.el8_2.x86_64.
Error building the module.  Build output follows.
make V=1 CONFIG_MODULE_SIG= CONFIG_MODULE_SIG_ALL= -C /lib/modules/4.18.0-193.19.1.el8_2.x86_64/build M=/tmp/vbox.0 SRCROOT=/tmp/vbox.0 -j1 modules
Makefile:978: *** "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel".  Stop.
make: *** [/tmp/vbox.0/Makefile-footer.gmk:117: vboxguest] Error 2
Could not find the X.Org or XFree86 Window System, skipping.
modprobe vboxguest failed

The important part of this error is

please install libelf-dev, libelf-devel or elfutils-libelf-devel

So, somehow, the dependency such as libelf-dev fails to install. It seems that. When I tried dnf -y install libelf-dev, I was angry that there was no such thing.

When I looked it up, it seemed to change to elfutils-libelf-devel, so I'll install it.

dnf install -y elfutils-libelf-devel

Exit CentOS and run vagrant reload. This solved the sync_folder error.