rdkafka-sys-4.10.0 depends on curl even without curl feature flag

[brocaar]

I'm trying to upgrade from rdkafka 0.38 to 0.39 and the build fails because rdkafka-sys 4.10.0 can't find curl/curl.h. Using previous versions, I did not see this error:

Cargo config:

    rdkafka = { version = "0.39", default-features = false, features = [
      "tokio",
      "cmake-build",
    ] }

Cargo lock:

[[package]]
name = "rdkafka"
version = "0.39.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d7956f9ac12b5712e50372d9749a3102f4810a8d42481c5eae3748d36d585bcf"
dependencies = [
 "futures-channel",
 "futures-util",
 "libc",
 "log",
 "rdkafka-sys",
 "serde",
 "serde_derive",
 "serde_json",
 "slab",
 "tokio",
]

[[package]]
name = "rdkafka-sys"
version = "4.10.0+2.12.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e234cf318915c1059d4921ef7f75616b5219b10b46e9f3a511a15eb4b56a3f77"
dependencies = [
 "cmake",
 "libc",
 "num_enum",
 "pkg-config",
]

Error:

  /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rdkafka-sys-4.10.0+2.12.1/librdkafka/src/rdkafka_conf.c:60:10: fatal error: curl/curl.h: No such file or directory
     60 | #include <curl/curl.h>
        |          ^~~~~~~~~~~~~
  compilation terminated.
  make[2]: *** [src/CMakeFiles/rdkafka.dir/build.make:244: src/CMakeFiles/rdkafka.dir/rdkafka_conf.c.o] Error 1
  make[2]: *** Waiting for unfinished jobs....
  make[1]: *** [CMakeFiles/Makefile2:116: src/CMakeFiles/rdkafka.dir/all] Error 2
  make: *** [Makefile:136: all] Error 2

[shdnx]

This is not a rust-rdkafka issue one but a librdkafka one: confluentinc/librdkafka#5230

[brocaar]

@shdnx thanks for your feedback. I was not aware about this issue. I only noticed the issue when upgrading the rdkafka crate, and thought it has something to do with the curl feature flag. Hopefully the above PR will get merged soon :)

[MingweiSamuel]

Can we locally patch the librdkafka source to workaround confluentinc/librdkafka#5230 ?

[svix-jplatte]

confluentinc/librdkafka#5136 was merged and released, I believe this just needs the C dependency to be upgraded now.