Problem with iesd failing while setting up a VM

[twindad]

Hi there!

I'm trying to set up a VM using VirtualBox to run a clean copy of Mavericks to test an application I am working on.

All the tutorials I have found say to download the Mavericks installer, then run "iesd" to create a DMG file that the VM can boot from to install the OS. The command given is:

iesd -i /Applications/Install\ OS\ X\ Mavericks.app -o Mavericks.dmg -t BaseSystem

When I try that, I get the following... every time...

➜  ~  iesd -i /Applications/Install\ OS\ X\ Mavericks.app -o Mavericks.dmg -t BaseSystem
==> Mounting /Applications/Install OS X Mavericks.app/Contents/SharedSupport/InstallESD.dmg
Mounted: /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s
==> Mounting /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s/BaseSystem.dmg
Mounted: /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1dh196f/d20150319-1034-yhvx31
==> Copying /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s/BaseSystem.dmg
Copied: /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1dh196f/d20150319-1034-yhvx31/BaseSystem.dmg
==> Copying /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s/BaseSystem.chunklist
Copied: /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1dh196f/d20150319-1034-yhvx31/BaseSystem.chunklist
==> Copying /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s/Packages
Copied: /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1dh196f/d20150319-1034-yhvx31/System/Installation/Packages
==> Unmounting /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s/BaseSystem.dmg
Failed during: /usr/bin/env hdiutil detach -quiet /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1dh196f/d20150319-1034-yhvx31
Error: Read-only file system - /var/folders/rc/v60fjqv961s99y7pp026g7300000gr/T/d20150319-1034-1cwl10s/.DS_Store

The only thing that changes is the path in /var/folders/... I always get the failure at the end with the Error: Read-only file system

And I wind up with no DMG file output.

I've Googled the heck out of this and can't find anywhere someone else has solved this, and I'm stumped.

Any help? What's going on? How can I fix it?

Thanks!!

- TD