Post-processor failed: open /packer_virtualbox-iso_virtualbox.box: permission denied

[vladshved]

$ packer build \
→   -var iso_url=../out/OSX_InstallESD_10.12.3_16D32.dmg \
→   -var update_system=0 \
→   -var autologin=true \
→   template.json

parallels-iso output will be in this color.
virtualbox-iso output will be in this color.
vmware-iso output will be in this color.

Warnings for build 'parallels-iso':

* A checksum type of 'none' was specified. Since ISO files are so big,
a checksum is highly recommended.

Warnings for build 'virtualbox-iso':

* A checksum type of 'none' was specified. Since ISO files are so big,
a checksum is highly recommended.

Warnings for build 'vmware-iso':

* A checksum type of 'none' was specified. Since ISO files are so big,
a checksum is highly recommended.

Build 'parallels-iso' errored: Failed creating Parallels driver: exec: "prlctl": executable file not found in $PATH
Build 'vmware-iso' errored: Failed creating VMware driver: Unable to initialize any driver for this platform. The errors
from each driver are shown below. Please fix at least one driver
to continue:
* Fusion application not found at path: /Applications/VMware Fusion.app
* Fusion application not found at path: /Applications/VMware Fusion.app

==> virtualbox-iso: Downloading or copying ISO
    virtualbox-iso: Downloading or copying: file:///Volumes/SSD%20750G/Users/vlad/Documents/vagrant/osx-vm-templates/out/OSX_InstallESD_10.12.3_16D32.dmg
==> virtualbox-iso: Creating virtual machine...
==> virtualbox-iso: Creating hard drive...
==> virtualbox-iso: Creating forwarded port mapping for communicator (SSH, WinRM, etc) (host port 2957)
==> virtualbox-iso: Executing custom VBoxManage commands...
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --audiocontroller hda
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --boot1 dvd
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --boot2 disk
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --chipset ich9
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --firmware efi
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --hpet on
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --keyboard usb
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --memory 2048
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --mouse usbtablet
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1496153385 --vram 128
    virtualbox-iso: Executing: storagectl packer-virtualbox-iso-1496153385 --name IDE Controller --remove
==> virtualbox-iso: Starting the virtual machine...
==> virtualbox-iso: Waiting 2s for boot...
==> virtualbox-iso: Typing the boot command...
==> virtualbox-iso: Waiting for SSH to become available...
==> virtualbox-iso: Connected to SSH!
==> virtualbox-iso: Uploading VirtualBox version info (5.1.22)
==> virtualbox-iso: Executing local command: sleep 0
==> virtualbox-iso: Uploading ../scripts/support/set_kcpassword.py => /private/tmp/set_kcpassword.py
==> virtualbox-iso: Provisioning with shell script: ../scripts/vagrant.sh
    virtualbox-iso: Installing vagrant keys for vagrant user
    virtualbox-iso: % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
    virtualbox-iso: Dload  Upload   Total   Spent    Left  Speed
    virtualbox-iso: 100   409  100   409    0     0    848      0 --:--:-- --:--:-- --:--:--   850
==> virtualbox-iso: Provisioning with shell script: ../scripts/vmware.sh
==> virtualbox-iso: Provisioning with shell script: ../scripts/parallels.sh
==> virtualbox-iso: Provisioning with shell script: ../scripts/xcode-cli-tools.sh
    virtualbox-iso: Software Update Tool
    virtualbox-iso: Copyright 2002-2015 Apple Inc.
    virtualbox-iso:
    virtualbox-iso:
    virtualbox-iso: Downloading Command Line Tools (macOS Sierra version 10.12) for Xcode
    virtualbox-iso: Downloaded Command Line Tools (macOS Sierra version 10.12) for Xcode
    virtualbox-iso: Installing Command Line Tools (macOS Sierra version 10.12) for Xcode
    virtualbox-iso: Done with Command Line Tools (macOS Sierra version 10.12) for Xcode
    virtualbox-iso: Done.
==> virtualbox-iso: Provisioning with shell script: ../scripts/chef-omnibus.sh
==> virtualbox-iso: Provisioning with shell script: ../scripts/puppet.sh
==> virtualbox-iso: Provisioning with shell script: ../scripts/add-network-interface-detection.sh
==> virtualbox-iso: Provisioning with shell script: ../scripts/autologin.sh
    virtualbox-iso: Enabling automatic GUI login for the 'vagrant' user..
==> virtualbox-iso: Provisioning with shell script: ../scripts/system-update.sh
==> virtualbox-iso: Provisioning with shell script: ../scripts/shrink.sh
==> virtualbox-iso: Gracefully halting virtual machine...
    virtualbox-iso: shutdown: / is busy updating; waiting for lock
    virtualbox-iso: Shutdown NOW!
    virtualbox-iso:
    virtualbox-iso: System shutdown time has arrived
==> virtualbox-iso: Preparing to export machine...
    virtualbox-iso: Deleting forwarded port mapping for the communicator (SSH, WinRM, etc) (host port 2957)
==> virtualbox-iso: Exporting virtual machine...
    virtualbox-iso: Executing: export packer-virtualbox-iso-1496153385 --output output-virtualbox-iso/packer-virtualbox-iso-1496153385.ovf
==> virtualbox-iso: Unregistering and deleting virtual machine...
==> virtualbox-iso: Running post-processor: vagrant
==> virtualbox-iso (vagrant): Creating Vagrant box for 'virtualbox' provider
    virtualbox-iso (vagrant): Copying from artifact: output-virtualbox-iso/packer-virtualbox-iso-1496153385-disk001.vmdk
    virtualbox-iso (vagrant): Copying from artifact: output-virtualbox-iso/packer-virtualbox-iso-1496153385.ovf
    virtualbox-iso (vagrant): Renaming the OVF to box.ovf...
Build 'virtualbox-iso' errored: 1 error(s) occurred:

* Post-processor failed: open /packer_virtualbox-iso_virtualbox.box: permission denied

==> Some builds didn't complete successfully and had errors:
--> parallels-iso: Failed creating Parallels driver: exec: "prlctl": executable file not found in $PATH
--> vmware-iso: Failed creating VMware driver: Unable to initialize any driver for this platform. The errors
from each driver are shown below. Please fix at least one driver
to continue:
* Fusion application not found at path: /Applications/VMware Fusion.app
* Fusion application not found at path: /Applications/VMware Fusion.app

--> virtualbox-iso: 1 error(s) occurred:

* Post-processor failed: open /packer_virtualbox-iso_virtualbox.box: permission denied

==> Builds finished but no artifacts were created.

[habsgoalie]

The packer template formulates an artifact output path (line 93 on template.json)-

"output": "{{user vagrant_box_directory}}/packer_{{.BuildName}}_{{.Provider}}.box"

that if not specified defaults to using an environment variable that probably isn't there. Happened to me as well. Seems like you can specify the vagrant_box_directory variable when you run packer or add it as an environment variable - PACKER_VAGRANT_BOX_DIR to work around this.