Fails to compile a valid build

[ckipp01]

I'm not really sure this is actually a Mill issue, but rather due to the recent changes in coursier. In my github-dependency-graph Mill plugin I came across a bug in coursier in the past about reconciled versions containing ranges. I added some hacks to work around it but recently with the pr to support the 0.12 series here I noticed that the behavior for this specific case changes a bit now and won't even compile when I believe it should. Given a minimal build like this:

import mill._, scalalib._

object minimalDep extends ScalaModule {
  def scalaVersion = "2.13.15"

  def ivyDeps = Agg(
    ivy"com.fasterxml.jackson.core:jackson-core:2.13.3"
  )
}

object minimal extends ScalaModule {
  def moduleDeps = Seq(minimalDep)

  def scalaVersion = "2.13.8"

  def ivyDeps = Agg(
    ivy"org.jongo:jongo:1.5.0"
  )
}

In earlier versions of Mill this would compile just fine. The reason I had this test is the jongo here wants a range of jackson data-bind [2.7.0,2.12.3] where jackson-core specifically wants 2.13.3. These should be compatible and 2.13.3 should be resolved and all should work fine. However, with 0.12.4 this no longer compiles:

[84/84] ============================== __.compile ============================== 3s
1 tasks failed
minimal.resolvedIvyDeps coursier.error.ResolutionError$ConflictingDependencies: Conflicting dependencies:
com.fasterxml.jackson.core:jackson-core:2.12.3 or [2.7.0,2.12.3] wanted by

  com.fasterxml.jackson.core:jackson-databind:2.12.3 wants 2.12.3
  └─ org.jongo:jongo:1.5.0 wants com.fasterxml.jackson.core:jackson-databind:[2.7.0,2.12.3]

  org.jongo:jongo:1.5.0 wants [2.7.0,2.12.3]


    mill.util.CoursierSupport.resolveDependenciesMetadataSafe(CoursierSupport.scala:312)
    mill.util.CoursierSupport.resolveDependenciesMetadataSafe$(CoursierSupport.scala:249)
    mill.util.Jvm$.resolveDependenciesMetadataSafe(Jvm.scala:15)
    mill.util.CoursierSupport.resolveDependenciesMetadataSafe(CoursierSupport.scala:339)
    mill.util.CoursierSupport.resolveDependenciesMetadataSafe$(CoursierSupport.scala:320)
    mill.util.Jvm$.resolveDependenciesMetadataSafe(Jvm.scala:15)
    mill.util.CoursierSupport.resolveDependencies(CoursierSupport.scala:80)
    mill.util.CoursierSupport.resolveDependencies$(CoursierSupport.scala:56)
    mill.util.Jvm$.resolveDependencies(Jvm.scala:15)
    mill.scalalib.Lib$.resolveDependencies(Lib.scala:158)
    mill.scalalib.CoursierModule$Resolver.resolveDeps(CoursierModule.scala:216)
    mill.scalalib.JavaModule.$anonfun$resolvedIvyDeps$3(JavaModule.scala:779)
coursier.error.ResolutionError$ConflictingDependencies: Conflicting dependencies:
com.fasterxml.jackson.core:jackson-core:2.12.3 or [2.7.0,2.12.3] wanted by

  com.fasterxml.jackson.core:jackson-databind:2.12.3 wants 2.12.3
  └─ org.jongo:jongo:1.5.0 wants com.fasterxml.jackson.core:jackson-databind:[2.7.0,2.12.3]

  org.jongo:jongo:1.5.0 wants [2.7.0,2.12.3]

Shouldn't these be compatible, 2.12.3 be resolved, and all compile fine?

[lefou]

I think this should resolve properly. Is this with Mill 0.12.4? Could you please verify, if this works with Mill 0.12.3? It is likely related to #3924. @alexarchambault Do you have an idea?

[ckipp01]

I think this should resolve properly. Is this with Mill 0.12.4? Could you please verify, if this works with Mill 0.12.3? It is likely related to #3924. @alexarchambault Do you have an idea?

So it looks like this broke in general with the 0.12.x series. I confirmed that it works with 0.11.13, but not with 0.12.0 and onwards.

[alexarchambault]

I think we're seeing two things here:

• since 0.12 and Use coursier 2.x API #3513, we report such conflicts (the coursier 2.x API handles that for us). Mill <= 0.11 used to trap those conflicts
• [2.7.0,2.12.3] and 2.12.3 ought to be compatible, indeed. That looks like a bug in coursier.

[alexarchambault]

@ckipp01 In the build example above, you're using 2.13.3 as a version for jackson-core. That's a typo, right? You meant 2.12.3? I can't reproduce the conflict with 2.12.3 on the command-line (I can't reproduce there the bug you seem to be running into)

[alexarchambault]

I would say the bug is in the conflict message of coursier, not in the resolver itself:

$ cs resolve com.fasterxml.jackson.core:jackson-core:2.12.3 org.jongo:jongo:1.5.0
com.fasterxml.jackson.core:jackson-annotations:2.12.3:default
com.fasterxml.jackson.core:jackson-core:2.12.3:default
com.fasterxml.jackson.core:jackson-databind:2.12.3:default
de.undercouch:bson4jackson:2.12.0:default
org.jongo:jongo:1.5.0:default

$ cs resolve com.fasterxml.jackson.core:jackson-core:2.13.3 org.jongo:jongo:1.5.0
Resolution error: Conflicting dependencies:
com.fasterxml.jackson.core:jackson-core:2.12.3 or [2.7.0,2.12.3] wanted by

  com.fasterxml.jackson.core:jackson-databind:2.12.3 wants 2.12.3
  └─ org.jongo:jongo:1.5.0 wants com.fasterxml.jackson.core:jackson-databind:[2.7.0,2.12.3]

  org.jongo:jongo:1.5.0 wants [2.7.0,2.12.3]

(it should have printed com.fasterxml.jackson.core:jackson-core:2.13.3 rather than com.fasterxml.jackson.core:jackson-core:2.12.3 in the second run)

[ckipp01]

@ckipp01 In the build example above, you're using 2.13.3 as a version for jackson-core. That's a typo, right? You meant 2.12.3? I can't reproduce the conflict with 2.12.3 on the command-line (I can't reproduce there the bug you seem to be running into)

ahhhh actually I did have 2.13.3 correctly, but was confused by the error message. The range is actually incompatible with 2.13.3, but I was focused on the error message which makes it seem like 2.12.3. So I guess this isn't an error here with Mill, or really an error at all in logic, just a confusing error message.