Works with HighSierra 10.13.6 and open Mojave Update 10.14.2.pkg -> Payload

[nsgrbr]

First: thanks the developer for the source code.

Payload file: macOSUpd10.14.2.dmg -> macOSUpd10.14.2.pkg (2.46 GB) -> macOSUpd10.14.2.pkg (1.65 GB) -> Payload (pbzx file).

Open Payload file with Hex Fiend app and verify the first line: pbz

https://support.apple.com/kb/DL1987?viewlocale=en_US&locale=en_US

https://ridiculousfish.com/hexfiend/

I tried opening the file macOSUpd10.14.2.pkg - 2.46 GB with Pacifist 3.6.1 but gave the error:

Crashed Thread:        5  Dispatch queue: com.apple.root.default-qos

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Application Specific Information:
*** Terminating app due to uncaught exception 'NSFileHandleOperationException', reason: '*** -[NSConcreteFileHandle writeData:]: Invalid argument'
terminating with uncaught exception of type NSException
abort() called

1 - I extracted the macOSUpd10.14.2.pkg - 2.46 GB with The Unarchiver.app 4.0.0 and extracted the following files.

https://itunes.apple.com/br/app/the-unarchiver/id425424353?l=en&mt=12

SecureBoot.pkg
macOSUpd10.14.2.RecoveryHDUpdate.pkg
macOSUpd10.14.2.pkg (1.65 GB)
macOSBrain.pkg
FullBundleUpdate.pkg
FirmwareUpdate.pkg
EmbeddedOSFirmware.pkg
Distribution

2 - Now the files that are inside macOSUpd10.14.2.pkg (1.65 GB) can be seen in the Finder -> right button mouse -> Show Package Contents -> copy Payload file to another folder/directory.

3 - Install Macports (need XCode installed). My system is HighSierra: MacPorts-2.5.4-10.13-HighSierra.pkg and reboot Mac OS system.

https://guide.macports.org/#installing.macports

4 - Update Macports - Finder -> Applications -> Utilities -> Terminal
sudo port selfupdate

5 - Install XZ (lzma.h) - /opt/local/include/lzma.h
sudo port install xz

6 - Install XAR (xar.h) - /opt/local/include/xar/xar.h
sudo port install xar

7 - Compile pbzx.c - source code in /Downloads/pbzx-master/pbzx.c
cd Downloads/pbzx-master/
clang -llzma -lxar -I /opt/local/include pbzx.c -o pbzx

8 - Copy Payload file to /Downloads/pbzx-master/ .

Executable files that are not in the system path need to be executed by putting before ". /" - Unix rules.
./pbzx -n Payload | cpio -i

9 - The following directories with their respective files will be created inside directory/folder /Downloads/pbzx-master/

Applications - 352,6 MB
bin - 4,9 MB
Library - 78,9 MB
private - 630 KB
sbin - 2,4 MB
System - 4,93 GB
usr - 528,2 MB