Can someone help with compiling PcapPlusPlus?

[IsaacsLab42]

I'm trying to use CPM to compile and statically link both libpcap and PcapPlusPlus, but I'm having problems. My CMakeLists.txt file looks like this:

CPMAddPackage(
    NAME libpcap
    GITHUB_REPOSITORY the-tcpdump-group/libpcap
    GIT_TAG libpcap-1.10.4
    OPTIONS
        "BUILD_SHARED_LIBS OFF"
        "BUILD_WITH_LIBNL OFf"
        "DISABLE_BLUETOOTH ON"
        "DISABLE_DAG OFF"
        "DISABLE_DBUS ON"
        "DISABLE_LINUX_USBMON ON"
        "DISABLE_NETMAP ON"
        "DISABLE_RDMA ON"
)

CPMAddPackage(
    NAME pcapplusplus
    GITHUB_REPOSITORY seladb/PcapPlusPlus
    GIT_TAG v23.09
    OPTIONS
        "BUILD_SHARED_LIBS OFF"
        "PCAPPP_USE_PF_RING OFF"
        "PCAPPP_USE_DPDK OFF"
        "PCAPPP_ENABLE_PCAP_IMMEDIATE_MODE ON"
        "PCAPPP_ENABLE_PCAP_SET_DIRECTION ON"
)

The error I get while PcapPlusPlus is configuring is:

PCAP library not found

So, I tried adding this to the CMakeLists.txt file in-between the two CPMAddPackage blocks:

if(libpcap_ADDED)
    set(PCAP_ROOT "${libpcap_BINARY_DIR}" CACHE STRING "" FORCE)
    set(PCAP_INCLUDE_DIR "${libpcap_SOURCE_DIR}" CACHE STRING "" FORCE)
    set(PCAP_LIBRARY "${libpcap_BINARY_DIR}/libpcap.a" CACHE STRING "" FORCE)
    # I've also tried set(PCAP_LIBRARY pcap_static CACHE STRING "" FORCE)
endif()

Now, the error changes to:

Couldn't determine how to link against libpcap

I finally managed to track down the cause of the error, as logged in the CMakeConfigureLog.yaml file:

ninja: error: '/home/user/src/build/debug/_deps/libpcap-build/libpcap.a', needed by 'cmTC_669c0', missing and no known rule to make it

Makes sense, since this is still the configure stage and libpcap.a has not been built yet. Is there any way to get around this problem? I'm totally onboard with adding a PATCH_COMMAND to munge one of the CMake files in either project, if that's what it takes. It just seems like there should be some other non-invasive solution though.

[k-channon-PA]

Have you tried running your cmake command with the --debug-output flag? Or even the --trace flag, if you want to see ALL THE THINGS!

You might be able to understand better what's causing the error with that output.

[IsaacsLab42]

Yes, I tried various traces and debug outputs. As I said, the problem is that the build is looking for libpcap.a to be there, before it has been built.