ScalaNative - unable to build when using uni::2026.1.13 (works with uni::2026.1.12 and earlier)

[dasm0012]

Hi,

It seems scala-cli is unable to build/run the HelloWorld example when using dep org.wvlet.uni::uni::2026.1.13 (2026.1.12 throws ld warning during linking but works, using uni version 2026.1.11 works with no issue)

---

Error message:
[info] Compiling to native code (5484 ms)
[info] Linking with [pthread, dl, m]
[error] /usr/bin/ld: warning: /home/luser/uniBook/.scala-build/uniBook_4a14478405/native/native/dependencies/nativelib_native0.5_3-0.5.12-5/scala-native/gc/shared/SafepointPollTrampoline-x86_64.S.o: missing .note.GNU-stack section implies executable stack
[error] /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
[error] /usr/bin/ld: /home/luser/uniBook/.scala-build/uniBook_4a14478405/native/native/dependencies/uni_native0.5_3-2026.1.13-1/scala-native/uni_curl_shim.c.o: in function uni_curl_easy_setopt_ptr': [error] uni_curl_shim.c:(.text+0x21): undefined reference to curl_easy_setopt'
[error] /usr/bin/ld: /home/luser/uniBook/.scala-build/uniBook_4a14478405/native/native/dependencies/uni_native0.5_3-2026.1.13-1/scala-native/uni_curl_shim.c.o: in function uni_curl_easy_setopt_long': [error] uni_curl_shim.c:(.text+0x51): undefined reference to curl_easy_setopt'
[error] /usr/bin/ld: /home/luser/uniBook/.scala-build/uniBook_4a14478405/native/native/dependencies/uni_native0.5_3-2026.1.13-1/scala-native/uni_curl_shim.c.o: in function uni_curl_easy_getinfo_long': [error] uni_curl_shim.c:(.text+0x81): undefined reference to curl_easy_getinfo'
[error] clang: error: linker command failed with exit code 1 (use -v to see invocation)
[info] Total (20714 ms)
Exception in thread "main" scala.scalanative.build.BuildException: Failed to link /home/luser/uniBook/.scala-build/uniBook_4a14478405/native/native/hello
at scala.scalanative.build.LLVM$.link(LLVM.scala:165)
....

Command line: scala-cli run . --native

//> using scala 3.8.4
// //> using platform native

//> using dep org.wvlet.uni::uni::2026.1.13

import wvlet.uni.log.LogSupport

class MyService extends LogSupport:
def greet(name: String): String =
info(s"Greeting $name")
s"Hello, $name!"

@main def hello =
val service = MyService()
println(service.greet("World"))

[xerial]

Fixed in v2026.1.17 (published to Maven Central).

Verified with your exact minimal example — swapping only the version dependency:

//> using scala 3.8.4
//> using platform native
//> using dep org.wvlet.uni::uni::2026.1.17

import wvlet.uni.log.LogSupport

class MyService extends LogSupport:
  def greet(name: String): String =
    info(s"Greeting $name")
    s"Hello, $name!"

@main def hello =
  val service = MyService()
  println(service.greet("World"))

$ scala-cli run hello.scala
...
[info] Linking with [pthread, dl, m]
...
Hello, World!

Root cause: the uni_curl_shim.c added in v2026.1.13 (PR #580) declared extern int curl_easy_setopt(...). Because Scala Native compiles resources/scala-native/*.c from every jar on the classpath unconditionally, that shim went into your binary even though your code only used LogSupport. -lcurl normally reaches the linker via @link("curl") on CurlBindings.Extern, but with CurlBindings unused, DCE strips it — leaving the shim's undefined refs unresolved.

Fix (PR #636): the shim now resolves curl_easy_setopt/curl_easy_getinfo lazily via dlsym(RTLD_DEFAULT, ...) inside a pthread_once init, instead of at C link time. The compiled .o no longer references any libcurl symbols, so unrelated Scala Native builds link cleanly. Projects that do use CurlBindings still work as before — @link("curl") pulls libcurl in, and RTLD_DEFAULT finds the symbols at runtime.

Please upgrade to 2026.1.17 and let us know if you hit anything else.