IssueTracker

Yeah it's not clear why some primitives were selected but others not. Both Long and Character seem to be missing. The absence of this support prevents the use of jvmTarget 1.8 in kotlinc. I'm going to raise the priority of this issue as a result.

$ cat Primitives.kt
data class Primitives(
  val aByte: Byte,
  val aBoolean: Boolean,
  val aChar: Char,
  val aDouble: Double,
  val aFloat: Float,
  val anInt: Int,
  val aLong: Long,
  val aShort: Short
)

$ kotlinc -jvm-target 1.8 *.kt

$ java -jar ~/dev/android/r8/build/libs/r8.jar --version
R8 1.5.14-dev
build engineering

$ java -jar ~/dev/android/r8/build/libs/r8.jar --lib $ANDROID_HOME/platforms/android-28/android.jar --release --output . *.class

$ dexdump -d classes.dex | egrep 'Ljava/lang/[a-zA-Z]+;\.hashCode:\([^\)]'
000ab8: 7110 1d00 0100                         |0012: invoke-static {v1}, Ljava/lang/Character;.hashCode:(C)I // method@001d
000b00: 7120 2600 2100                         |0036: invoke-static {v1, v2}, Ljava/lang/Long;.hashCode:(J)I // method@0026

Sent https://r8-review.googlesource.com/c/r8/+/36620

$ git -C ~/dev/android/r8 log --oneline | head -1
fd9c23137 Add desugaring of Java 8 Long|Character.hashCode methods

$ java -jar ~/dev/android/r8/build/libs/d8.jar --output . --release *.class

$ dexdump -d classes.dex | egrep 'Ljava/lang/[a-zA-Z]+;\.hashCode:\([^\)]' | wc -l
       0

Project: r8
Branch: master

commit db49dbc78dc4a4da9d0be0c32a135bef50689343
Author: Jake Wharton <jakew@google.com>
Date:   Wed Apr 03 11:07:55 2019

    Add desugaring of Java 8 Long and Character methods
   
    Bug: 129730297
    Test: Java8MethodsTest
    Change-Id: Ibe67e8677ba4650a6ef30acf66ebcfeb8437aa02

M       src/main/java/com/android/tools/r8/ir/desugar/Java8MethodRewriter.java
M       src/test/java/com/android/tools/r8/desugar/Java8MethodsTest.java

https://r8-review.googlesource.com/36620

Should hit canary in a few weeks

Which canary version received it?

This is not in canary yet, if you really need to try it out you should be able to do:
buildscript {

    repositories {
        maven {
            url "http://storage.googleapis.com/r8-releases/raw/master"
        }
    }

    dependencies {
        classpath 'com.android.tools:r8:db49dbc78dc4a4da9d0be0c32a135bef50689343'  // Must be before the Gradle Plugin for Android.
        classpath 'com.android.tools.build:gradle:3.0.1'
     }
}

Project: r8
Branch: d8-1.4

commit d136eee65fb2e7f89f8199cd34f495fb3e83f0d4
Author: Rico Wind <ricow@google.com>
Date:   Tue Apr 16 14:05:37 2019

    Version 1.4.88
   
    Cherry pick: Add desugaring of Java 8 Long and Character methods
    CL: https://r8-review.googlesource.com/c/r8/+/36620
   
    Bug:  129730297
    Change-Id: I3ac7df7277dfea4d49b0633ba7d05c5a4241e03b

M       src/main/java/com/android/tools/r8/Version.java
M       src/main/java/com/android/tools/r8/ir/desugar/Java8MethodRewriter.java
M       src/test/java/com/android/tools/r8/desugar/Java8MethodsTest.java

https://r8-review.googlesource.com/37102

Is there any way to check what version of AGP this will ship with (alpha, beta, etc...)?

Seems to be fixed in AGP 3.4 final

AGP 3.4 contains R8 1.4.77 and this change is not included.

There will be 3.4.1 release (around Google I/O), and as per comment #9, the fix is on board.

Meanwhile, you can use comment #9 by editing your top-level gradle file like this:

buildscript {

    repositories {
        maven {
            url 'http://storage.googleapis.com/r8-releases/raw'
        }
    }

    dependencies {
        classpath 'com.android.tools:r8:1.4.88'  // Must be before the Gradle Plugin for Android.
        classpath 'com.android.tools.build:gradle:3.4.0'
     }
}

Is it finally fixed?