I want to use rdkafka's static library，but i have some problems

[Z-J-X]

After I compiled and installed the latest version of rdkafka on CentOS 7, there were some warnings
WARNING: librdkafka-static.a: Not creating self-contained static library librdkafka-static.a: no static libraries available/enabled
I don't have any problems compiling demo programs using dynamic libraries，But when I wanted to compile with a static library, an error occurred.

/usr/local/lib/librdkafka.a(rdkafka.o): In function `rd_kafka_destroy_internal':
/root/data/librdkafka/src/rdkafka.c:1175: undefined reference to `pthread_kill'
/usr/local/lib/librdkafka.a(rdkafka.o): In function `rd_kafka_new':
/root/data/librdkafka/src/rdkafka.c:2408: undefined reference to `pthread_sigmask'
/root/data/librdkafka/src/rdkafka.c:2476: undefined reference to `pthread_sigmask'
/root/data/librdkafka/src/rdkafka.c:2180: undefined reference to `pthread_once'
/root/data/librdkafka/src/rdkafka.c:2449: undefined reference to `pthread_sigmask'
/usr/local/lib/librdkafka.a(rdkafka.o): In function `rd_kafka_destroy_app':
/root/data/librdkafka/src/rdkafka.c:1075: undefined reference to `pthread_kill'
/usr/local/lib/librdkafka.a(rdkafka.o): In function `rd_kafka_global_init':
/root/data/librdkafka/src/rdkafka.c:166: undefined reference to `pthread_once'
/usr/local/lib/librdkafka.a(rdkafka_broker.o): In function `rd_crc32_update':
/root/data/librdkafka/src/rdcrc32.h:128: undefined reference to `crc32'
/usr/local/lib/librdkafka.a(rdkafka_broker.o): In function `rd_kafka_broker_add':
/root/data/librdkafka/src/rdkafka_broker.c:5551: undefined reference to `pthread_sigmask'
/root/data/librdkafka/src/rdkafka_broker.c:5643: undefined reference to `pthread_sigmask'
/root/data/librdkafka/src/rdkafka_broker.c:5602: undefined reference to `pthread_sigmask'
/usr/local/lib/librdkafka.a(rdkafka_broker.o): In function `rd_crc32_update':
/root/data/librdkafka/src/rdcrc32.h:128: undefined reference to `crc32'
/root/data/librdkafka/src/rdcrc32.h:128: undefined reference to `crc32'
/root/data/librdkafka/src/rdcrc32.h:128: undefined reference to `crc32'
/root/data/librdkafka/src/rdcrc32.h:128: undefined reference to `crc32'
/root/data/librdkafka/src/rdcrc32.h:128: undefined reference to `crc32'
/usr/local/lib/librdkafka.a(rdkafka_broker.o):/root/data/librdkafka/src/rdcrc32.h:128: more undefined references to `crc32' follow
/usr/local/lib/librdkafka.a(rdkafka_broker.o): In function `rd_kafka_broker_thread_main':
/root/data/librdkafka/src/rdkafka_broker.c:5374: undefined reference to `ERR_remove_thread_state'
/usr/local/lib/librdkafka.a(rdkafka_msg.o): In function `rd_crc32_init':
/root/data/librdkafka/src/rdcrc32.h:100: undefined reference to `crc32'
/usr/local/lib/librdkafka.a(rdkafka_msg.o): In function `rd_crc32_update':
......

My approach is to remove ‘/usr/local/lib/librdkafka++.so’ and ‘librdkafka.so’, and then let the compiler choose to use 'librdkafka++.a' and 'librdkafka.a'
So I guess the static library needs this file librdkafka-static.a，but I don't know how to generate it
Please help me~~

[edenhill]

The static library still uses some dynamically system libraries, such as pthreads.
Recommend that you use pkg-config --libs --static rdkafka or pkg-config --libs --static rdkafka-static to get the extra libraries you need to link.

[Z-J-X]

Ok. Thank you very much. I have succeeded in your way