Apple releases new macOS betas pretty frequently and you test all of those betas, right? Well what if I told you there are some features you can’t test. Not because you don’t want to but because Apple doesn’t give you the tools.

Apple just released macOS 10.13.4 beta 2 on Feb. 6, 2018. However, if you wanted to test this new release with Apple’s own Device Enrollment Program (DEP) you can’t! Or can you?

With some inspiration from @groob, @tvsutton, & @fuzzylogiq. Along with a little code inspiration from @frogor, @gregneagle & @magervalp. The following hacky method was created.

Requirements

Process

Please note this process is not 100% clean and might install beta software onto the root drive running 10.13 so it is highly recommended you do not use your primary machine unless it is already on the beta track. Remember “hacky” above?

  1. Use autodmg with a 10.13.x installer to create a dmg.

    Using Autodmg

  2. Mount the 10.13.X ouput dmg with.

    hdiutil attach -owners on /path/to/10.13.3.dmg -shadow

# output
expected   CRC32 $FC3036F4
/dev/disk5         	EF57347C-0000-11AA-AA11-0030654
/dev/disk5s1       	41504653-0000-11AA-AA11-0030654	/Volumes/Macintosh HD 1
/dev/disk5s2       	41504653-0000-11AA-AA11-0030654	/Volumes/Preboot
/dev/disk5s3       	41504653-0000-11AA-AA11-0030654	/Volumes/Recovery 1
/dev/disk4          	GUID_partition_scheme
/dev/disk4s1        	EFI
/dev/disk4s2        	Apple_APFS

    Info

    Note your disk number: ‘/dev/disk5’ from the above output
    Note your mount path: ‘/Volumes/Macintosh HD 1’ from the above output

  3. Launch SUS Inspector.

  4. If this is your first time using SUS Inspector you will be asked if you want to add custom catalogs which we do. If you have already configured SUS and didn’t add these seed catalogs see 1.

    Adding custom catalogs

  5. Add the following additional Apple catalogs into the feed window.

    Feed NameFeed URL
    DeveloperSeedhttp://swscan.apple.com/content/catalogs/others/index-10.13seed-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
    PublicSeedhttp://swscan.apple.com/content/catalogs/others/index-10.13beta-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
    CustomerSeedhttp://swscan.apple.com/content/catalogs/others/index-10.13customerseed-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

    Info

    Tip: SUS Inspector is an alpha release. When you copy/paste the Name and URL hit “enter” on the keyboard after each item is added. Once all three feeds have been added click “save”.

  6. Let SUS Inspector sync the catalogs.

    SUS Inspector syncing catalogs

  7. Use the CustomerSeed or PublicSeed to find the latest 10.13.X combo update beta.

  8. Right click the item, select “Get Info”, change to packages tab, download all of them.

    Finding and downloading the right files

  9. Once the download is complete click reveal.

  10. Now we will modify the XXX-English.dist file to disregard all safety checks essentially allowing us to always install. Remember “hacky” method?

    sed -i '' 's/return false/return true/g' /path/to/091-65991.English.dist

  11. Use an undocumented option to install from the dist file directly to the shadow mounted dmg. Make sure to change the Volumes path if it is named differently.

    sudo installer -pkg /path/to/091-65991.English.dist -tgt /Volumes/Macintosh\ HD\ 1

  12. Unmount the shadow dmg.

    hdiutil detach /dev/disk<number_from_step2>

  13. Convert the shadow dmg to compressed dmg.

    hdiutil convert -format UDZO -o 10.13.4b2.dmg /path/to/10.13.3.dmg -shadow

  14. Now you will want to delete shadow file manually. It will be next to your 10.13.3.dmg with .shadow extension.

This dmg can now be used in vfuse, imaging, etc. for DEP testing.

Other thoughts

This is not a valid solution. I would love for Apple to properly distribute a real macOS Install XXX Beta.app file with each beta. This would allow admins and other members of the community (VMware, Parallels, etc.) to properly to test against beta releases. For example the startosinstall command is completely untestable right now and the above hacky method does not allow us to validate changes until Apple releases full point releases, which often is too late.

  1. Close SUS Inspector and delete the following directory ~/Library/Application Support/SUS Inspector/SUS_Inspector.storedata see the following link for more info ↩︎