Using SwiftKafka for watchOS

[MFabi23]

I am developing a watchOS app, that uses data coming from a Kafkastream and I want to use this library for this purpose, but it keeps ignoring my local "librdkafka" library.

Detailed error description:

• Warnings:

1. ignoring file /usr/local/Cellar/librdkafka/1.3.0/lib/librdkafka.dylib, building for watchOS-arm64_32 but attempting to link with file built for macOS-x86_64

• Errors:
  Undefined symbol: _rd_kafka_produce
  Undefined symbol: _rd_kafka_poll
  Undefined symbol: _rd_kafka_conf_dump
  Undefined symbol: _rd_kafka_topic_name
  Undefined symbol: _rd_kafka_consumer_close
  Undefined symbol: _rd_kafka_consumer_poll
  Undefined symbol: _rd_kafka_flush
  Undefined symbol: _rd_kafka_brokers_add
  Undefined symbol: _rd_kafka_commit
  Undefined symbol: _rd_kafka_topic_partition_list_new
  Undefined symbol: _rd_kafka_topic_partition_list_destroy
  Undefined symbol: _rd_kafka_message_destroy
  Undefined symbol: _rd_kafka_topic_new
  Undefined symbol: _rd_kafka_topic_partition_list_add
  Undefined symbol: _rd_kafka_subscribe
  Undefined symbol: _rd_kafka_conf_set_dr_msg_cb
  Undefined symbol: _rd_kafka_conf_set
  Undefined symbol: _rd_kafka_conf_dup
  Undefined symbol: _rd_kafka_conf_new
  Undefined symbol: _rd_kafka_conf_destroy
  Undefined symbol: _rd_kafka_conf_dump_free
  Undefined symbol: _rd_kafka_poll_set_consumer
  Undefined symbol: _rd_kafka_topic_destroy
  Undefined symbol: _rd_kafka_assign
  Undefined symbol: _rd_kafka_new
  Undefined symbol: _rd_kafka_destroy

What I did:

1. Installed librdkafka

• brew install librdkafka

2. Created app

• Created a new watchOS standalone app in Xcode
• Added a new SwiftPackage with the built-in SPM from Xcode using the URL from your GitHub SwiftKafka project
• Added SwiftKafka to "Link Binary With Libraries" in my WatchKit Extension

3. Build the App -> Build failed with above errors

[MFabi23]

I tried with the AppleWatch simulators and a real AppleWatch Series 4 as target device.

[winsmith]

To compile librdkafka with Xcode, do these two things:

1. brew install librdkafka
2. add this to the target section of your Package.swift:

linkerSettings: [
    .unsafeFlags(["-Xlinker", "-L/usr/local/lib"], .when(platforms: [.macOS]))
]

I know this comment is old but I just finally figured this out and I'm overjoyed to share!

source: #11 (comment)