rte_eth_dev_count_avail() from the DPDK API returns 0 intel x550 ethernet card on linux 5.4.0 dpdk version 19.11.12 - dpdk

Question

built dpdk 19.11.12 from source and i have written an ext app built using these libraries. I use dpdk-devbind to bind a device to igb_uio .
The device i have is an Intel X550. When i run testpmd it seems to recognize the device but int my app rte_eth_dev_count_avail always returns 0
I would belive this has to either do with the way i have built my dpdk library or my app
this is extract of the Makefile i am using to build my app
RTE_SDK ?= /usr/local/share/dpdk
RTE_TARGET ?= x86_64-default-linuxapp-gcc
include $(RTE_SDK)/mk/rte.vars.mk
# binary name
APP = myapp
# all source are stored in SRCS-y
SRCS-y := main.c
WERROR_FLAGS += -Werror
CFLAGS += -O3 -g
CFLAGS += $(WERROR_FLAGS) -Wno-address-of-packed-member
CFLAGS += -Wall
CFLAGS += -pie -fPIE -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -fstack-protector-strong
CFLAGS += -DSTATSD
LDFLAGS += -z relro -z now
LDFLAGS += -ljansson -lrte_pmd_ixgbe
LDLIBS += -lrte_pmd_ixgbe
# disable since libxenstore.so isn't linked properly
#CONFIG_RTE_LIBRTE_PMD_XENVIRT = n
CONFIG_RTE_LIBRTE_PMD_IXGBE = y
include $(RTE_SDK)/mk/rte.extapp.mk
I build my dpdk libraries using this
RUN make -C /dpdk/dpdk-stable-${DPDK_VERSION}/ config T=x86_64-native-linuxapp-gcc
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_BUILD_SHARED_LIB=n/CONFIG_RTE_BUILD_SHARED_LIB=y/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LIBRTE_ETHDEV_DEBUG=n/CONFIG_RTE_LIBRTE_ETHDEV_DEBUG=y/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LIBRTE_E1000_DEBUG_RX=n/CONFIG_RTE_LIBRTE_E1000_DEBUG_RX=y/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LIBRTE_E1000_DEBUG_TX=n/CONFIG_RTE_LIBRTE_E1000_DEBUG_TX=y/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LIBRTE_IXGBE_DEBUG_RX=n/CONFIG_RTE_LIBRTE_IXGBE_DEBUG_RX=y/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LIBRTE_IXGBE_DEBUG_TX=n/CONFIG_RTE_LIBRTE_IXGBE_DEBUG_TX=y/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LOG_DP_LEVEL=RTE_LOG_INFO/CONFIG_RTE_LOG_DP_LEVEL=RTE_LOG_DEBUG/g > /tmp/out && mv /tmp/out build/.config
RUN cd /dpdk/dpdk-stable-${DPDK_VERSION}/ && cat build/.config | sed -e s/CONFIG_RTE_LOG_HISTORY=256/CONFIG_RTE_LOG_HISTORY=2048/g > /tmp/out && mv /tmp/out build/.config
i can bind to the interfaces using dpdk-devbind and testpmd also seems to identify and be able to bind to these devices
but my app is not able to recognize the devices.
What am i missing here ?
these are the logs --log-level=8 for EAL logs and I get this output
Sep 09 04:56:50 {"timestamp": 1662717410.8821511, "level": "info", "message": "Initialising EAL ..."}
Sep 09 04:56:50 EAL: Detected 64 lcore(s)
Sep 09 04:56:50 EAL: Detected 2 NUMA nodes
Sep 09 04:56:50 EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
Sep 09 04:56:50 EAL: Selected IOVA mode 'PA'
Sep 09 04:56:50 EAL: No available hugepages reported in hugepages-1048576kB
Sep 09 04:56:50 EAL: Debug dataplane logs available - lower performance
Sep 09 04:56:50 EAL: Debug dataplane logs available - lower performance
Sep 09 04:56:50 EAL: Probing VFIO support...
Sep 09 04:56:50 EAL: VFIO support initialized
Sep 09 04:56:50 EAL: Probing VFIO support...
Sep 09 04:56:50 EAL: VFIO support initialized
also adding the -d parameter with the directory where the plugins are located /usr/local/lib/ gives me an error where the plugin is not found
the eal param initialized is
--master-lcore 4 -l 4,5,6,7 --log-level 8 -d /usr/local/lib/
Sep 09 04:47:29 EAL: Detected 64 lcore(s)
Sep 09 04:47:29 EAL: Detected 2 NUMA nodes
Sep 09 04:47:29 EAL: librte_compressdev.so.0.200: cannot open shared object file: No such file or directory
Sep 09 04:47:29 EAL: FATAL: Cannot init plugins
Sep 09 04:47:29 EAL: Cannot init plugins
the librte_compressdev.so.0.200 is present in the path
ls -l /usr/local/lib/librte_compressdev.so.0.200
-rwxr-xr-x 1 root root 38024 Sep 8 23:51 /usr/local/lib/librte_compressdev.so.0.200

Answer 1

[based on the live debug]
DPDK 17.11 LTS use libdpdk.so and a complete shared library, which makes all the necessary ethdev PMD available. hence using the current makefile, it pans out properly without any issues.
But moving to DPDK 19.11 LTS, libdpdk.so is no longer availble. hence one have to manually link either in shared or static libraries properly (as pointed out in comments). For example
DPDK_CFLAGS=" -DHAVE_DPDK -I${RTE_SDK}/${RTE_TARGET}/include/ -include ${RTE_SDK}/${RTE_TARGET}/include/rte_config.h "
DPDK_LDFLAGS="-I$RTE_SDK/lib/librte_eal/linux/eal/include \
-DRTE_USE_FUNCTION_VERSIONING \
-I$RTE_SDK/$RTE_TARGET/include -include $RTE_SDK/$RTE_TARGET/include/rte_config.h \
-D_GNU_SOURCE -W -Wall -DALLOW_EXPERIMENTAL_API \
-L$RTE_SDK/$RTE_TARGET/lib -Wl,-lrte_flow_classify -Wl,--whole-archive -Wl,-lrte_pipeline -Wl,--no-whole-archive \
-Wl,--whole-archive -Wl,-lrte_table -Wl,--no-whole-archive -Wl,--whole-archive \
-Wl,-lrte_port -Wl,--no-whole-archive -Wl,-lrte_pdump -Wl,-lrte_ip_frag -Wl,-lrte_meter \
-Wl,-lrte_fib -Wl,-lrte_rib -Wl,-lrte_lpm -Wl,-lrte_acl -Wl,-lrte_power -Wl,-lrte_kni \
-Wl,-lrte_efd -Wl,-lrte_bpf -Wl,-lrte_ipsec -Wl,--whole-archive -Wl,-lrte_cfgfile -Wl,-lrte_gro \
-Wl,-lrte_gso -Wl,-lrte_hash -Wl,-lrte_member -Wl,-lrte_vhost -Wl,-lrte_kvargs -Wl,-lrte_mbuf \
-Wl,-lrte_net -Wl,-lrte_ethdev -Wl,-lrte_cryptodev -Wl,-lrte_security -Wl,-lrte_compressdev \
-Wl,-lrte_eventdev -Wl,-lrte_timer -Wl,-lrte_mempool -Wl,-lrte_stack -Wl,-lrte_mempool_ring \
-Wl,-lrte_ring -Wl,-lrte_pci -Wl,-lrte_eal -Wl,-lrte_cmdline -Wl,-lrte_reorder -Wl,-lrte_sched \
-Wl,-lrte_rcu -Wl,-lrte_bus_pci -Wl,-lrte_bus_vdev -Wl,-lrte_mempool_bucket -Wl,-lrte_mempool_stack \
-Wl,-lrte_pmd_af_packet \
-Wl,-lrte_pmd_ixgbe \
-Wl,-lrte_pmd_memif \
-Wl,-lrte_pmd_null \
-Wl,-lpcap -Wl,-lrte_pmd_ring -Wl,-lrte_pmd_tap -Wl,-lrte_pmd_virtio -Wl,-lrte_bus_vmbus \
-Wl,-lcrypto -Wl,-lrte_pmd_null_crypto -Wl,-lrte_pmd_crypto_scheduler -Wl,-lrte_pmd_virtio_crypto \
-Wl,-lrte_pmd_skeleton_event -Wl,-lrte_pmd_sw_event \
-Wl,--no-whole-archive -Wl,-lrt -Wl,-lm -Wl,-lnuma -Wl,-ldl -Wl,-export-dynamic -Wl,-export-dynamic \
-L$RTE_SDK/examples/l2fwd/build/lib -L$RTE_SDK/$RTE_TARGET/lib -Wl,--as-needed"
Since DPDk 19.11 LTS makes uses on meson-ninja, my suggestion and recommendation is to make use of pkg-config to built the right CFLAGS and LDFLAGS. Please refer StackOverflow query on using dpdk cmake too
Note: recommended to build a custom target folder rather than make install, since the built and application run is done in docker.