How to work with http maven repository?

[lakako]

When set 'export COURSIER_REPOSITORIES=http://xxxxx:8082/repository/maven-public/'

It will cause

java.lang.RuntimeException: coursier.error.ResolutionError$CantDownloadModule: Error downloading com.lihaoyi:mill-runner-daemon_3:1.1.6
  download error: Caught java.net.MalformedURLException (Accessing a URL protocol that was not enabled. The URL protocol http is supported but not enabled by default. It must be enabled by adding the --enable-url-protocols=http option to the native-image command.) while downloading http://xxxx:8082/repository/maven-public/com/lihaoyi/mill-runner-daemon_3/1.1.6/mill-runner-daemon_3-1.1.6.pom
        at scala.sys.package$.error(package.scala:28)
        at mill.launcher.CoursierClient$.resolveMillDaemon$$anonfun$2(CoursierClient.scala:93)                                                                                                                           at mill.launcher.CoursierClient$.cached(CoursierClient.scala:47)
        at mill.launcher.CoursierClient$.resolveMillDaemon(CoursierClient.scala:99)
        at mill.launcher.MillLauncherMain$.main0(MillLauncherMain.scala:63)
        at mill.launcher.MillLauncherMain$.main(MillLauncherMain.scala:18)
        at mill.launcher.MillLauncherMain.main(MillLauncherMain.scala)

Mill launcher failed. See out/mill-launcher/log for details.

How to work with http repository?

[krotname]

This is not a COURSIER_REPOSITORIES syntax issue. The failure is coming from the Mill native launcher before Coursier can actually download the artifact:

URL protocol http is supported but not enabled by default

Mill 1.x uses a Graal native launcher by default on supported platforms, and the bootstrap script lets you opt into the JVM launcher by adding the -jvm suffix to the Mill version. The docs also show COURSIER_REPOSITORIES examples with https://..., which avoids this path entirely.

Best options:

# preferred: expose the repository over HTTPS
export COURSIER_REPOSITORIES=https://xxxxx:8082/repository/maven-public/
./mill resolve _

or, if that repository is only available over plain HTTP, force the JVM launcher:

export MILL_VERSION=1.1.6-jvm
export COURSIER_REPOSITORIES=http://xxxxx:8082/repository/maven-public/
./mill resolve _

You can also put 1.1.6-jvm in .mill-version if this should be project-wide.

Rebuilding the native launcher with --enable-url-protocols=http would also explain the error, but that is a build-time native-image option, not something you can add to COURSIER_REPOSITORIES at runtime.