pdfsplit fails to start pdfsplit returns the following error when launched from terminal:

pdfsplit --version
-bash: /usr/local/bin/pdfsplit: Bad CPU type in executable


OS: macOS Catalina 10.15.2

file

Checking architecture.

file /usr/local/bin/pdfsplit
/usr/local/bin/pdfsplit: Mach-O universal binary with 2 architectures: [ppc:Mach-O executable ppc] [i386:Mach-O executable i386]
/usr/local/bin/pdfsplit (for architecture ppc): Mach-O executable ppc
/usr/local/bin/pdfsplit (for architecture i386):    Mach-O executable i386
That file only has binaries for PPC and 32-bit Intel, so it won't run on Catalina. 

You need to see the following line for a 64-bit binary:

Mach-O 64-bit executable x86_64


Either see if there's an updated version from the developer, or use one of the many other command line tools for splitting PDFs: GhostScript, CPDF, or even python tools that call MacOS Quartz routines. 

Off the CLI, there's even an Automator action that will do it.

Here's my own python script, which runs natively on Catalina, creating a folder with all the split pages inside.

https://github.com/benwiggy/PDFsuite/blob/master/Automator_Scripts/splitPDF.py