32.x building (without cmake) protobuf against static libraries - absl linking problems

[flipkickmedia]

What version of protobuf and what language are you using?
Version: 32.x C++

What operating system (Linux, Windows, ...) and version?
Ubuntu 24.04

What runtime / compiler are you using (e.g., python version or gcc version)
gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0

What did you do?
Build absl libraries manually:

# abseil - needs to be an LTS version - 20250512.1
cd "${DEPENDENCIES_BASE_PATH}" || exit
git clone https://github.com/abseil/abseil-cpp.git "${DEPENDENCIES_BASE_PATH}/abseil-cpp/source"
cd abseil-cpp/source || exit
git clean -f -d
git fetch --tags
git checkout lts_2025_08_14
mkdir ../build
cd ../build || exit
cmake                                                                    \
  -DCMAKE_CXX_STANDARD=17                                                \
  -DCMAKE_INSTALL_PREFIX="${DEPENDENCIES_BASE_PATH}/abseil-cpp/install"  \
  -DABSL_BUILD_TESTING=OFF                                               \
  -DABSL_USE_GOOGLETEST_HEAD=OFF                                         \
  ../source
cmake --build . --target install
cd "${rootDir}" || exit

Build protobuf libraries manually

# protobuf - working
cd "${DEPENDENCIES_BASE_PATH}" || exit
git clone https://github.com/protocolbuffers/protobuf.git -b 32.x "${DEPENDENCIES_BASE_PATH}/protobuf/source"
cd protobuf/source || exit
git clean -f -d
mkdir ../build
cd ../build || exit
cmake                                                                      \
  -DCMAKE_CXX_STANDARD=17                                                  \
  -DCMAKE_INSTALL_PREFIX="${DEPENDENCIES_BASE_PATH}/protobuf/install"      \
  -Dabsl_DIR="${DEPENDENCIES_BASE_PATH}/abseil-cpp/install/lib/cmake/absl" \
  -DZLIB_LIBRARY="${DEPENDENCIES_BASE_PATH}/zlib/install/lib/libz.a"       \
  -DZLIB_INCLUDE_DIR="${DEPENDENCIES_BASE_PATH}/zlib/install/include"      \
  -Dprotobuf_INSTALL=ON                                                    \
  -Dprotobuf_BUILD_TESTS=OFF                                               \
  -Dprotobuf_BUILD_CONFORMANCE=OFF                                         \
  -Dprotobuf_BUILD_EXAMPLES=OFF                                            \
  -Dprotobuf_FORCE_FETCH_DEPENDENCIES=OFF                                  \
  -Dprotobuf_LOCAL_DEPENDENCIES_ONLY=OFF                                   \
  ../source
cmake --build . --target install
cd "${rootDir}" || exit

Libraries are built ok

Next I built my messages.proto into messages.pb.cc.

Using cmake I tried to build a static messagespb lib and then link that into my main program, that failed. I got lots of absl undefined reference errors.

Then I tried this:

#
#add_library(messagespb STATIC
#        src/proto/messages.pb.cc
#)
#target_include_directories(messagespb PUBLIC
#        ${CMAKE_SOURCE_DIR}/_deps/protobuf/install/include
#        ${CMAKE_SOURCE_DIR}/_deps/abseil-cpp/install/include

file(GLOB_RECURSE ABSL_LIBS ${CMAKE_SOURCE_DIR}/_deps/abseil-cpp/install/lib/*.a)
message("ABSL LIBS: ${ABSL_LIBS}")

#target_link_libraries(messagespb PUBLIC
#        ${CMAKE_SOURCE_DIR}/_deps/protobuf/install/lib/libprotobuf.a
#        ${ABSL_LIBS}
#)

add_executable(Server server_ws.cc src/proto/messages.pb.cc)
target_include_directories(Server PUBLIC
        ${CMAKE_SOURCE_DIR}/src
        ${CMAKE_SOURCE_DIR}/_deps/protobuf/install/include
        ${CMAKE_SOURCE_DIR}/_deps/abseil-cpp/install/include
)
target_link_libraries(Server PUBLIC
        ${CMAKE_SOURCE_DIR}/_deps/protobuf/install/lib/libprotobuf.a
        ${ABSL_LIBS}
)

and ended up with

/usr/bin/cmake --build /home/tshaw/Documents/uwebsockets-cmake/cmake-build-debug --target Server -j 6
[0/1] Re-running CMake...
ABSL LIBS: <-- truncated to avoid listing them all out -->
-- Configuring done (0.1s)
-- Generating done (0.0s)
-- Build files have been written to: /home/tshaw/Documents/uwebsockets-cmake/cmake-build-debug
[2/3] Linking CXX executable Server
FAILED: Server 
: && /usr/bin/c++ -g -Wl,--dependency-file=CMakeFiles/Server.dir/link.d CMakeFiles/Server.dir/server_ws.cc.o CMakeFiles/Server.dir/src/proto/messages.pb.cc.o -o Server  -Wl,-rpath,/home/tshaw/Documents/uwebsockets-cmake/_deps/ImageMagick/install/lib:/home/tshaw/Documents/uwebsockets-cmake/_deps/lsquic/install/lib:/home/tshaw/Documents/uwebsockets-cmake/_deps/boringssl/install/lib  /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libprotobuf.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_base.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_city.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_civil_time.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cord.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cord_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_functions.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_handle.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_sample_token.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc32c.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc_cord_state.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc_cpu_detect.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_debugging_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_decode_rust_punycode.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_demangle_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_demangle_rust.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_die_if_null.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_examine_stack.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_exponential_biased.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_failure_signal_handler.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_commandlineflag.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_commandlineflag_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_config.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_marshalling.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_parse.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_private_handle_accessor.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_program_name.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_reflection.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_usage.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_flags_usage_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_graphcycles_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_hash.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_hashtable_profiler.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_hashtablez_sampler.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_int128.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_kernel_timeout_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_leak_check.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_entry.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_flags.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_globals.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_initialize.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_check_op.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_conditions.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_fnmatch.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_format.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_globals.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_log_sink_set.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_message.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_nullguard.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_proto.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_structured_proto.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_severity.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_sink.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_malloc_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_periodic_sampler.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_poison.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_profile_builder.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_distributions.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_distribution_test_util.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_entropy_pool.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_platform.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_randen.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_randen_hwaes.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_randen_hwaes_impl.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_randen_slow.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_internal_seed_material.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_seed_gen_exception.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_random_seed_sequences.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_raw_hash_set.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_raw_logging_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_scoped_set_env.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_spinlock_wait.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_stacktrace.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_status.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_statusor.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_str_format_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_strerror.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_string_view.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_strings.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_strings_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_symbolize.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_synchronization.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_throw_delegate.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_time.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_time_zone.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_tracing_internal.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_utf8_for_code_point.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_vlog_config_internal.a  libuSockets.a  /home/tshaw/Documents/uwebsockets-cmake/_deps/lsquic/install/lib/liblsquic.so  /home/tshaw/Documents/uwebsockets-cmake/_deps/boringssl/install/lib/libcrypto.so  /home/tshaw/Documents/uwebsockets-cmake/_deps/boringssl/install/lib/libssl.so  /home/tshaw/Documents/uwebsockets-cmake/_deps/zlib/install/lib/libz.a && :
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_conditions.a(conditions.cc.o): warning: relocation against `_ZN4absl12lts_2025081413base_internal10CycleClock19cycle_clock_source_E' in read-only section `.text._ZN4absl12lts_2025081413base_internal10CycleClock20LoadCycleClockSourceEv[_ZN4absl12lts_2025081413base_internal10CycleClock20LoadCycleClockSourceEv]'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libprotobuf.a(generated_message_tctable_lite.cc.o): in function `utf8_range::IsStructurallyValid(std::basic_string_view<char, std::char_traits<char> >)':
generated_message_tctable_lite.cc:(.text._ZN10utf8_range19IsStructurallyValidESt17basic_string_viewIcSt11char_traitsIcEE[_ZN10utf8_range19IsStructurallyValidESt17basic_string_viewIcSt11char_traitsIcEE]+0x40): undefined reference to `utf8_range_IsValid'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libprotobuf.a(parse_context.cc.o): in function `utf8_range::SpanStructurallyValid(std::basic_string_view<char, std::char_traits<char> >)':
parse_context.cc:(.text._ZN10utf8_range21SpanStructurallyValidESt17basic_string_viewIcSt11char_traitsIcEE[_ZN10utf8_range21SpanStructurallyValidESt17basic_string_viewIcSt11char_traitsIcEE]+0x40): undefined reference to `utf8_range_ValidPrefix'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::cord_internal::CordzInfo::Head(absl::lts_20250814::cord_internal::CordzSnapshot const&)':
cordz_info.cc:(.text+0x98a): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::DiagnosticsHandleIsSafeToInspect(absl::lts_20250814::cord_internal::CordzHandle const*) const'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::cord_internal::CordzInfo::Next(absl::lts_20250814::cord_internal::CordzSnapshot const&) const':
cordz_info.cc:(.text+0xac3): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::DiagnosticsHandleIsSafeToInspect(absl::lts_20250814::cord_internal::CordzHandle const*) const'
/usr/bin/ld: cordz_info.cc:(.text+0xaea): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::DiagnosticsHandleIsSafeToInspect(absl::lts_20250814::cord_internal::CordzHandle const*) const'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::cord_internal::CordzInfo::CordzInfo(absl::lts_20250814::cord_internal::CordRep*, absl::lts_20250814::cord_internal::CordzInfo const*, absl::lts_20250814::cord_internal::CordzUpdateTracker::MethodIdentifier, long)':
cordz_info.cc:(.text+0x10d1): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::~CordzHandle()'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::cord_internal::CordzInfo::~CordzInfo()':
cordz_info.cc:(.text+0x114d): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::~CordzHandle()'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::cord_internal::CordzInfo::Untrack()':
cordz_info.cc:(.text+0x14da): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::SafeToDelete() const'
/usr/bin/ld: cordz_info.cc:(.text+0x155b): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::Delete(absl::lts_20250814::cord_internal::CordzHandle*)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::base_internal::SpinLock::lock()':
cordz_info.cc:(.text._ZN4absl12lts_2025081413base_internal8SpinLock4lockEv[_ZN4absl12lts_2025081413base_internal8SpinLock4lockEv]+0x2b): undefined reference to `absl::lts_20250814::base_internal::SpinLock::SlowLock()'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::base_internal::SpinLock::unlock()':
cordz_info.cc:(.text._ZN4absl12lts_2025081413base_internal8SpinLock6unlockEv[_ZN4absl12lts_2025081413base_internal8SpinLock6unlockEv]+0xc1): undefined reference to `absl::lts_20250814::base_internal::SpinLock::SlowUnlock(unsigned int)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o): in function `absl::lts_20250814::cord_internal::CordzHandle::CordzHandle()':
cordz_info.cc:(.text._ZN4absl12lts_2025081413cord_internal11CordzHandleC2Ev[_ZN4absl12lts_2025081413cord_internal11CordzHandleC5Ev]+0x1d): undefined reference to `absl::lts_20250814::cord_internal::CordzHandle::CordzHandle(bool)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_cordz_info.a(cordz_info.cc.o):(.data.rel.ro._ZTIN4absl12lts_2025081413cord_internal9CordzInfoE[_ZTIN4absl12lts_2025081413cord_internal9CordzInfoE]+0x10): undefined reference to `typeinfo for absl::lts_20250814::cord_internal::CordzHandle'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc_cord_state.a(crc_cord_state.cc.o): in function `absl::lts_20250814::crc_internal::CrcCordState::Checksum() const':
crc_cord_state.cc:(.text+0x449): undefined reference to `absl::lts_20250814::RemoveCrc32cPrefix(absl::lts_20250814::crc32c_t, absl::lts_20250814::crc32c_t, unsigned long)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc_cord_state.a(crc_cord_state.cc.o): in function `absl::lts_20250814::crc_internal::CrcCordState::NormalizedPrefixCrcAtNthChunk(unsigned long) const':
crc_cord_state.cc:(.text+0x57d): undefined reference to `absl::lts_20250814::RemoveCrc32cPrefix(absl::lts_20250814::crc32c_t, absl::lts_20250814::crc32c_t, unsigned long)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_crc_cord_state.a(crc_cord_state.cc.o): in function `absl::lts_20250814::crc_internal::CrcCordState::Normalize()':
crc_cord_state.cc:(.text+0x6ab): undefined reference to `absl::lts_20250814::RemoveCrc32cPrefix(absl::lts_20250814::crc32c_t, absl::lts_20250814::crc32c_t, unsigned long)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_hash.a(hash.cc.o): in function `absl::lts_20250814::hash_internal::(anonymous namespace)::SplitAndCombineOn32Bit(unsigned char const*, unsigned long, unsigned long)':
hash.cc:(.text+0x706): undefined reference to `absl::lts_20250814::hash_internal::CityHash32(char const*, unsigned long)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_check_op.a(check_op.cc.o): in function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >* absl::lts_20250814::IgnoreLeak<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)':
check_op.cc:(.text._ZN4absl12lts_2025081410IgnoreLeakINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEPT_S9_[_ZN4absl12lts_2025081410IgnoreLeakINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEPT_S9_]+0x18): undefined reference to `absl::lts_20250814::DoIgnoreLeak(void const*)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_conditions.a(conditions.cc.o): in function `absl::lts_20250814::base_internal::CycleClock::LoadCycleClockSource()':
conditions.cc:(.text._ZN4absl12lts_2025081413base_internal10CycleClock20LoadCycleClockSourceEv[_ZN4absl12lts_2025081413base_internal10CycleClock20LoadCycleClockSourceEv]+0x10): undefined reference to `absl::lts_20250814::base_internal::CycleClock::cycle_clock_source_'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_conditions.a(conditions.cc.o): in function `absl::lts_20250814::base_internal::CycleClock::Frequency()':
conditions.cc:(.text._ZN4absl12lts_2025081413base_internal10CycleClock9FrequencyEv[_ZN4absl12lts_2025081413base_internal10CycleClock9FrequencyEv]+0x9): undefined reference to `absl::lts_20250814::base_internal::UnscaledCycleClock::Frequency()'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_message.a(log_message.cc.o): in function `absl::lts_20250814::log_internal::LogMessage::LogMessageData::LogMessageData(char const*, int, absl::lts_20250814::LogSeverity, absl::lts_20250814::Time)':
log_message.cc:(.text+0x376): undefined reference to `absl::lts_20250814::ShouldPrependLogPrefix()'
/usr/bin/ld: log_message.cc:(.text+0x3b0): undefined reference to `absl::lts_20250814::base_internal::GetCachedTID()'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_message.a(log_message.cc.o): in function `absl::lts_20250814::log_internal::LogMessage::LogMessageData::FinalizeEncodingAndFormat()':
log_message.cc:(.text+0x657): undefined reference to `absl::lts_20250814::log_internal::ThreadIsLoggingToLogSink()'

What did you expect to see
I was hoping to be able to create a library that has the protobuf de/encoding functionality

What did you see instead?
Linking errors to absl dispite the libs being linked

Im happy to make this work differently but I want to avoid using cmake to bring in the protobuf and absl projects. My ideal scenario is that I can create a library that I can use in other projects without having to use cmake to bring in protobuf into every project. I would think that is achieveable and reasonable.

Fingers crossed and thanks :)

[flipkickmedia]

I also tried letting protobuf download the absl source from github using -Dprotobuf_FORCE_FETCH_DEPENDENCIES=ON . Using this method I get considerably less errors:

====================[ Build | Server | Debug ]==================================
/usr/bin/cmake --build /home/tshaw/Documents/uwebsockets-cmake/cmake-build-debug --target Server -j 6
[0/1] Re-running CMake...
ABSL LIBS: <-- removed -->
-- Configuring done (0.2s)
-- Generating done (0.0s)
-- Build files have been written to: /home/tshaw/Documents/uwebsockets-cmake/cmake-build-debug
[1/2] Linking CXX executable Server
FAILED: Server 
: && /usr/bin/c++ -g -Wl,--dependency-file=CMakeFiles/Server.dir/link.d CMakeFiles/Server.dir/server_ws.cc.o CMakeFiles/Server.dir/src/proto/messages.pb.cc.o -o Server  -Wl,-rpath, <-- libs removed -->

usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libabsl_symbolize.a(symbolize.cc.o): in function `absl::lts_20250512::InitializeSymbolizer(char const*)':
symbolize.cc:(.text+0x11): undefined reference to `absl::lts_20250512::debugging_internal::VDSOSupport::Init()'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libabsl_symbolize.a(symbolize.cc.o): in function `absl::lts_20250512::debugging_internal::DemangleInplace(char*, unsigned long, char*, unsigned long)':
symbolize.cc:(.text+0x2c88): undefined reference to `absl::lts_20250512::debugging_internal::Demangle(char const*, char*, unsigned long)'
/usr/bin/ld: /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libabsl_symbolize.a(symbolize.cc.o): in function `absl::lts_20250512::debugging_internal::(anonymous namespace)::Symbolizer::GetUncachedSymbol(void const*)':
symbolize.cc:(.text+0x3988): undefined reference to `absl::lts_20250512::debugging_internal::VDSOSupport::VDSOSupport()'
/usr/bin/ld: symbolize.cc:(.text+0x39b6): undefined reference to `absl::lts_20250512::debugging_internal::VDSOSupport::LookupSymbolByAddress(void const*, absl::lts_20250512::debugging_internal::ElfMemImage::SymbolInfo*) const'
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

[flipkickmedia]

Next up I tried building absl and protobuf as shared libraries. This result is interesting because whilst my program compiles, when running the program I get errors about missing absl so libraries.

tshaw@laptop-entitywind:~/Documents/uwebsockets-cmake/cmake-build-debug$ ./Server
./Server: error while loading shared libraries: libabsl_die_if_null.so.2508.0.0: cannot open shared object file: No such file or directory

so did an ldd on my executable

tshaw@laptop-entitywind:~/Documents/uwebsockets-cmake/cmake-build-debug$ ldd ./Server
        linux-vdso.so.1 (0x00007ffef79d5000)
        libMagick++-7.Q16HDRI.so.5 => /home/tshaw/Documents/uwebsockets-cmake/_deps/ImageMagick/install/lib/libMagick++-7.Q16HDRI.so.5 (0x00007635ea2a2000)
        libcrypto.so => /home/tshaw/Documents/uwebsockets-cmake/_deps/boringssl/install/lib/libcrypto.so (0x00007635ea000000)
        libssl.so => /home/tshaw/Documents/uwebsockets-cmake/_deps/boringssl/install/lib/libssl.so (0x00007635e9f77000)
        libprotobuf.so.32.2.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libprotobuf.so.32.2.0 (0x00007635e9600000)
        libabsl_log_internal_check_op.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_check_op.so.2508.0.0 (0x00007635ea296000)
        libabsl_log_internal_message.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_message.so.2508.0.0 (0x00007635ea26f000)
        libabsl_log_internal_nullguard.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_nullguard.so.2508.0.0 (0x00007635ea26a000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007635e9200000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007635e9f49000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007635e8e00000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007635e9517000)
        libMagickWand-7.Q16HDRI.so.10 => /home/tshaw/Documents/uwebsockets-cmake/_deps/ImageMagick/install/lib/libMagickWand-7.Q16HDRI.so.10 (0x00007635e90b5000)
        libMagickCore-7.Q16HDRI.so.10 => /home/tshaw/Documents/uwebsockets-cmake/_deps/ImageMagick/install/lib/libMagickCore-7.Q16HDRI.so.10 (0x00007635e8800000)
        libabsl_die_if_null.so.2508.0.0 => not found
        libabsl_statusor.so.2508.0.0 => not found
        libutf8_validity.so.32.2.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libutf8_validity.so.32.2.0 (0x00007635ea243000)
        /lib64/ld-linux-x86-64.so.2 (0x00007635ea3dc000)
        libabsl_log_internal_conditions.so.2508.0.0 => not found
        libabsl_raw_hash_set.so.2508.0.0 => not found
        libabsl_status.so.2508.0.0 => not found
        libabsl_cord.so.2508.0.0 => not found
        libabsl_cordz_info.so.2508.0.0 => not found
        libabsl_cord_internal.so.2508.0.0 => not found
        libabsl_hash.so.2508.0.0 => not found
        libabsl_synchronization.so.2508.0.0 => not found
        libabsl_time.so.2508.0.0 => not found
        libabsl_time_zone.so.2508.0.0 => not found
        libabsl_str_format_internal.so.2508.0.0 => not found
        libabsl_strings.so.2508.0.0 => not found
        libabsl_spinlock_wait.so.2508.0.0 => not found
        libabsl_throw_delegate.so.2508.0.0 => not found
        libabsl_raw_logging_internal.so.2508.0.0 => not found
        libabsl_leak_check.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_leak_check.so.2508.0.0 (0x00007635e9f42000)
        libabsl_strings.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_strings.so.2508.0.0 (0x00007635e9f02000)
        libabsl_examine_stack.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_examine_stack.so.2508.0.0 (0x00007635e9efd000)
        libabsl_log_internal_format.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_format.so.2508.0.0 (0x00007635e9ef1000)
        libabsl_log_internal_structured_proto.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_structured_proto.so.2508.0.0 (0x00007635e9ee5000)
        libabsl_strerror.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_strerror.so.2508.0.0 (0x00007635e9edf000)
        libabsl_log_internal_log_sink_set.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_log_sink_set.so.2508.0.0 (0x00007635e9ece000)
        libabsl_log_internal_globals.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_globals.so.2508.0.0 (0x00007635e9511000)
        libabsl_log_globals.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_globals.so.2508.0.0 (0x00007635e9504000)
        libabsl_log_internal_proto.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_internal_proto.so.2508.0.0 (0x00007635e94fd000)
        libabsl_time.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_time.so.2508.0.0 (0x00007635e94cc000)
        libabsl_strings_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_strings_internal.so.2508.0.0 (0x00007635e94c4000)
        libabsl_throw_delegate.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_throw_delegate.so.2508.0.0 (0x00007635e94bd000)
        libabsl_base.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_base.so.2508.0.0 (0x00007635e94af000)
        libabsl_raw_logging_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_raw_logging_internal.so.2508.0.0 (0x00007635e94a8000)
        libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x00007635e86c3000)
        libgomp.so.1 => /lib/x86_64-linux-gnu/libgomp.so.1 (0x00007635e905f000)
        libjbig.so.0 => /lib/x86_64-linux-gnu/libjbig.so.0 (0x00007635e9498000)
        liblcms2.so.2 => /lib/x86_64-linux-gnu/liblcms2.so.2 (0x00007635e8d9e000)
        libtiff.so.6 => /lib/x86_64-linux-gnu/libtiff.so.6 (0x00007635e8d11000)
        libjpeg.so.8 => /lib/x86_64-linux-gnu/libjpeg.so.8 (0x00007635e8640000)
        liblqr-1.so.0 => /lib/x86_64-linux-gnu/liblqr-1.so.0 (0x00007635e9487000)
        libpng16.so.16 => /lib/x86_64-linux-gnu/libpng16.so.16 (0x00007635e9027000)
        libdjvulibre.so.21 => /lib/x86_64-linux-gnu/libdjvulibre.so.21 (0x00007635e8490000)
        libfontconfig.so.1 => /lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007635e843f000)
        libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007635e8373000)
        libwebpmux.so.3 => /lib/x86_64-linux-gnu/libwebpmux.so.3 (0x00007635e9019000)
        libwebpdemux.so.2 => /lib/x86_64-linux-gnu/libwebpdemux.so.2 (0x00007635e947e000)
        libwebp.so.7 => /lib/x86_64-linux-gnu/libwebp.so.7 (0x00007635e82f8000)
        libXext.so.6 => /lib/x86_64-linux-gnu/libXext.so.6 (0x00007635e8cfd000)
        liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007635e82c6000)
        libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 (0x00007635e8ce9000)
        libOpenEXR-3_1.so.30 => /lib/x86_64-linux-gnu/libOpenEXR-3_1.so.30 (0x00007635e7e00000)
        libOpenEXRCore-3_1.so.30 => /lib/x86_64-linux-gnu/libOpenEXRCore-3_1.so.30 (0x00007635e824b000)
        libopenjp2.so.7 => /lib/x86_64-linux-gnu/libopenjp2.so.7 (0x00007635e81ea000)
        libpangocairo-1.0.so.0 => /lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007635e81d9000)
        libpango-1.0.so.0 => /lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007635e816e000)
        libgobject-2.0.so.0 => /lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007635e810b000)
        libcairo.so.2 => /lib/x86_64-linux-gnu/libcairo.so.2 (0x00007635e7cbc000)
        libxml2.so.2 => /lib/x86_64-linux-gnu/libxml2.so.2 (0x00007635e7ada000)
        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007635e7abe000)
        libabsl_stacktrace.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_stacktrace.so.2508.0.0 (0x00007635e7ab7000)
        libabsl_symbolize.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_symbolize.so.2508.0.0 (0x00007635e7aaa000)
        libabsl_str_format_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_str_format_internal.so.2508.0.0 (0x00007635e7a57000)
        libabsl_log_sink.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_log_sink.so.2508.0.0 (0x00007635e8106000)
        libabsl_synchronization.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_synchronization.so.2508.0.0 (0x00007635e7a2f000)
        libabsl_spinlock_wait.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_spinlock_wait.so.2508.0.0 (0x00007635e7a28000)
        libabsl_hash.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_hash.so.2508.0.0 (0x00007635e7a21000)
        libabsl_time_zone.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_time_zone.so.2508.0.0 (0x00007635e79c0000)
        libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x00007635e7997000)
        libzstd.so.1 => /lib/x86_64-linux-gnu/libzstd.so.1 (0x00007635e78db000)
        libLerc.so.4 => /lib/x86_64-linux-gnu/libLerc.so.4 (0x00007635e7854000)
        libdeflate.so.0 => /lib/x86_64-linux-gnu/libdeflate.so.0 (0x00007635e7841000)
        libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007635e76f8000)
        libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007635e76cc000)
        libbrotlidec.so.1 => /lib/x86_64-linux-gnu/libbrotlidec.so.1 (0x00007635e76bc000)
        libsharpyuv.so.0 => /lib/x86_64-linux-gnu/libsharpyuv.so.0 (0x00007635e76b4000)
        libImath-3_1.so.29 => /lib/x86_64-linux-gnu/libImath-3_1.so.29 (0x00007635e7666000)
        libIlmThread-3_1.so.30 => /lib/x86_64-linux-gnu/libIlmThread-3_1.so.30 (0x00007635e765c000)
        libIex-3_1.so.30 => /lib/x86_64-linux-gnu/libIex-3_1.so.30 (0x00007635e75d9000)
        libpangoft2-1.0.so.0 => /lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007635e75bc000)
        libharfbuzz.so.0 => /lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007635e74af000)
        libgio-2.0.so.0 => /lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007635e72df000)
        libfribidi.so.0 => /lib/x86_64-linux-gnu/libfribidi.so.0 (0x00007635e72c1000)
        libthai.so.0 => /lib/x86_64-linux-gnu/libthai.so.0 (0x00007635e72b6000)
        libffi.so.8 => /lib/x86_64-linux-gnu/libffi.so.8 (0x00007635e72a8000)
        libXrender.so.1 => /lib/x86_64-linux-gnu/libXrender.so.1 (0x00007635e729c000)
        libxcb-render.so.0 => /lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007635e728d000)
        libxcb-shm.so.0 => /lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007635e7288000)
        libpixman-1.so.0 => /lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007635e71d9000)
        libicuuc.so.74 => /lib/x86_64-linux-gnu/libicuuc.so.74 (0x00007635e6e00000)
        libabsl_debugging_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_debugging_internal.so.2508.0.0 (0x00007635e71cd000)
        libabsl_malloc_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_malloc_internal.so.2508.0.0 (0x00007635e71c2000)
        libabsl_demangle_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_demangle_internal.so.2508.0.0 (0x00007635e71b3000)
        libabsl_int128.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_int128.so.2508.0.0 (0x00007635e71aa000)
        libabsl_graphcycles_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_graphcycles_internal.so.2508.0.0 (0x00007635e719c000)
        libabsl_kernel_timeout_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_kernel_timeout_internal.so.2508.0.0 (0x00007635e7192000)
        libabsl_tracing_internal.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_tracing_internal.so.2508.0.0 (0x00007635e718d000)
        libabsl_city.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_city.so.2508.0.0 (0x00007635e7187000)
        libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x00007635e7181000)
        libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007635e7177000)
        libpcre2-8.so.0 => /lib/x86_64-linux-gnu/libpcre2-8.so.0 (0x00007635e70dd000)
        libbrotlicommon.so.1 => /lib/x86_64-linux-gnu/libbrotlicommon.so.1 (0x00007635e70ba000)
        libgraphite2.so.3 => /lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007635e7094000)
        libgmodule-2.0.so.0 => /lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007635e708d000)
        libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007635e703e000)
        libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007635e7011000)
        libdatrie.so.1 => /lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007635e6df7000)
        libicudata.so.74 => /lib/x86_64-linux-gnu/libicudata.so.74 (0x00007635e5000000)
        libabsl_demangle_rust.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_demangle_rust.so.2508.0.0 (0x00007635e6df0000)
        libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007635e6dda000)
        libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007635e6d9f000)
        libabsl_decode_rust_punycode.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_decode_rust_punycode.so.2508.0.0 (0x00007635e6d9a000)
        libmd.so.0 => /lib/x86_64-linux-gnu/libmd.so.0 (0x00007635e6d8b000)
        libabsl_utf8_for_code_point.so.2508.0.0 => /home/tshaw/Documents/uwebsockets-cmake/_deps/abseil-cpp/install/lib/libabsl_utf8_for_code_point.so.2508.0.0 (0x00007635e6d86000)

This is the strange thing, you can see from the ldd output some of the absl libs are linked correctly.

So lets run an strace and see where the program is looking for the libs:

tshaw@laptop-entitywind:~/Documents/uwebsockets-cmake/cmake-build-debug$ strace ./Server
 # only important bits provided

openat(AT_FDCWD, "/home/tshaw/Documents/uwebsockets-cmake/_deps/protobuf/install/lib/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v4/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v4/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/", {st_mode=S_IFDIR|0755, st_size=200704, ...}, 0) = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v4/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v4/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/", {st_mode=S_IFDIR|0755, st_size=200704, ...}, 0) = 0
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v4/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v4/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v3/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v3/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v2/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v2/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v4/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v4/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v3/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v3/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v2/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v2/", 0x7ffcd6ce2e30, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/libabsl_die_if_null.so.2508.0.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
writev(2, [{iov_base="./Server", iov_len=8}, {iov_base=": ", iov_len=2}, {iov_base="error while loading shared libra"..., iov_len=36}, {iov_base=": ", iov_len=2}, {iov_base="libabsl_die_if_null.so.2508.0.0", iov_len=31}, {iov_base=": ", iov_len=2}, {iov_base="cannot open shared object file", iov_len=30}, {iov_base=": ", iov_len=2}, {iov_base="No such file or directory", iov_len=25}, {iov_base="\n", iov_len=1}], 10./Server: error while loading shared libraries: libabsl_die_if_null.so.2508.0.0: cannot open shared object file: No such file or directory

So the libs are being searched for inside the protobuf lib dir (which doesnt exist since I installed abseil myself)

This seems to be a problem with protobuf.

Next Im gonna try and look inside the cmakelists for protobuf and see if we can track down the absl (seemingly hardcoded) paths

As a workaround it seems the absl shared libs need to be in the same folder as the protobuf libs.

Ill try statically linking using the same method.

This shouldnt be happening and explains why so many people are having issues linking absl.