As you can see, this breaks a bunch of stuff (which was to be expected on second thought). I need to spend more time thinking about how I'd like this to look in the end (positive vs. negative defaults and naming conventions). I'll come back to this later.

As you can see, this breaks a bunch of stuff (which was to be expected on second thought). I need to spend more time thinking about how I'd like this to look in the end (positive vs. negative defaults and naming conventions). I'll come back to this later.

I see the problem. There care cases where core/CMakeLists.txt is being imported without the top-level CMakeLists.txt, which causes all the ENABLE_* vars to be undefined (no formats/codes enabled). I added the following to core/CMakeLists.txt to default to ON if not defined. This should make this change a NOP to existing users that do not set these variables:

# If parent CMakeLists.txt does not define ZXING_ENABLE_... options, set them to ON.
foreach(format 1D AZTEC DATAMATRIX MAXICODE PDF417 QRCODE)
    set(_var "ZXING_ENABLE_${format}")
    if (NOT DEFINED ${_var})
        set(${_var} ON CACHE BOOL "Enable support for ${format} barcodes" FORCE)
    endif()
endforeach()

Can you retry the workflow?

Thanks a lot. I had some additional cleanup that I wanted to add but did not have access to your PR repo/branch. So I merged it as is and added my changes in master.