Improve Build Times in Less Time

Build times are never as fast as we want but there is a lot you can do to improve them today without being a Gradle domain expert or buying everyone new computers! In this talk we'll cover a number of different tools, patterns, and common pitfalls to avoid for improving your build times quickly and take your (team's) developer productivity to the next level.

Transcript

1. Zac Sweers – Slack – @ZacSweers
   Improve Build Times in
   Less Time
   https://speakerdeck.com/zacsweers/improve-build-times-in-less-time
   

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2. Non
   -
   goals
   

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3. Goals
   

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4. Goals
   https://twitter.com/inyaki_mwc/status/1486091593295695874?s=20&t=RgLHt1bWRcyLXp1oL4qL8A
   

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5. Gradle Refresher
   

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6. Gradle Refresher
   • Tasks
   
   
   • Projects
   
   
   • Plugins
   
   
   • Conf
   i
   gurations
   
   
   • Conf
   i
   guration
   • Caching/Incremental
   Builds
   
   
   • Incremental
   Compilation (IC)
   
   
   • Daemons
   
   
   • Annotation Processing
   

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7. Tasks
   @CacheableTask
   abstract class PrintMessageTask : DefaultTask() {
   @get:Input
   abstract val inputMessage: Property
   @get:OutputFile
   abstract val outputFile: RegularFileProperty
   @TaskAction
   fun run() {
   val message = inputMessage.get()
   println(message)
   outputFile.asFile.get().writeText(message)
   }
   }
   

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8. Tasks
   • Inputs and outputs
   @CacheableTask
   abstract class PrintMessageTask : DefaultTask() {
   @get:Input
   abstract val inputMessage: Property
   @get:OutputFile
   abstract val outputFile: RegularFileProperty
   @TaskAction
   fun run() {
   val message = inputMessage.get()
   println(message)
   outputFile.asFile.get().writeText(message)
   }
   }
   

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9. Tasks
   • Inputs and outputs
   
   • Parallelizable
   @CacheableTask
   abstract class PrintMessageTask : DefaultTask() {
   @get:Input
   abstract val inputMessage: Property
   @get:OutputFile
   abstract val outputFile: RegularFileProperty
   @TaskAction
   fun run() {
   val message = inputMessage.get()
   println(message)
   outputFile.asFile.get().writeText(message)
   }
   }
   

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10. Tasks
    • Inputs and outputs
    
    • Parallelizable
    
    • Task action
    @CacheableTask
    abstract class PrintMessageTask : DefaultTask() {
    @get:Input
    abstract val inputMessage: Property
    @get:OutputFile
    abstract val outputFile: RegularFileProperty
    @TaskAction
    fun run() {
    val message = inputMessage.get()
    println(message)
    outputFile.asFile.get().writeText(message)
    }
    }
    

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11. Tasks
    • Inputs and outputs
    
    • Parallelizable
    
    • Task action
    
    • Cacheability
    @CacheableTask
    abstract class PrintMessageTask : DefaultTask() {
    @get:Input
    abstract val inputMessage: Property
    @get:OutputFile
    abstract val outputFile: RegularFileProperty
    @TaskAction
    fun run() {
    val message = inputMessage.get()
    println(message)
    outputFile.asFile.get().writeText(message)
    }
    }
    

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12. Tasks
    • Inputs and outputs
    
    • Parallelizable
    
    • Task action
    
    • Cacheability
    @CacheableTask
    abstract class PrintMessageTask : DefaultTask() {
    @get:Input
    abstract val inputMessage: Property
    @get:OutputFile
    abstract val outputFile: RegularFileProperty
    @TaskAction
    fun run() {
    val message = inputMessage.get()
    println(message)
    outputFile.asFile.get().writeText(message)
    }
    }
    

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13. Tasks
    • Inputs and outputs
    
    • Parallelizable
    
    • Task action
    
    • Cacheability
    
    • Con
    fi
    gured at con
    fi
    guration-time
    
    • Should be lazy!
    project.tasks.register("printMessage") {
    inputMessage.set("Hello World!")
    outputFile.set(
    project.layout.buildDirectory.
    fi
    le(
    "outputs/logs/message.txt"))
    }
    

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14. Tasks
    • Inputs and outputs
    
    • Parallelizable
    
    • Task action
    
    • Cacheability
    
    • Con
    fi
    gured at con
    fi
    guration-time
    
    • Should be lazy!
    @CacheableTask
    abstract class PrintMessageTask : DefaultTask() {
    @get:Input
    abstract val inputMessage: Property
    @get:OutputFile
    abstract val outputFile: RegularFileProperty
    @TaskAction
    fun run() {
    val message = inputMessage.get()
    println(message)
    outputFile.asFile.get().writeText(message)
    }
    }
    

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15. Tasks
    • Inputs and outputs
    
    • Parallelizable
    
    • Task action
    
    • Cacheability
    
    • Con
    fi
    gured at con
    fi
    guration-time
    
    • Should be lazy!
    
    • Some common types (SourceTask,
    CompileTask, etc)
    @CacheableTask
    abstract class PrintMessageTask : DefaultTask() {
    @get:Input
    abstract val inputMessage: Property
    @get:OutputFile
    abstract val outputFile: RegularFileProperty
    @TaskAction
    fun run() {
    val message = inputMessage.get()
    println(message)
    outputFile.asFile.get().writeText(message)
    }
    }
    

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16. Tasks
    

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17. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    

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18. Projects
    • Projects contain a set of tasks
    
    • Also contain things like source
    sets
    
    • Can have subprojects
    
    • Every directory in between is
    technically a project
    
    • Can have plugins applied to
    them
    

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19. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    

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20. Plugins
    • Reusable implementations of gradle logic
    
    • Well known examples
    
    • Android Gradle Plugin (AGP)
    
    • Kotlin Gradle Plugin (KGP)
    
    • Many 1st-party plugins
    
    • Ours too! github.com/slackhq/slack-gradle-plugin
    plugins {
    kotlin("jvm")
    id("com.android.library")
    `java-platform`
    }
    

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21. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    

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22. Conf
    i
    gurations
    • Essentially named
    fi
    le collections
    
    • “implementation”, “api”, etc
    dependencies {
    implementation("com.squareup.moshi:moshi:1.13.0")
    testImplementation("junit:junit:4.13")
    }
    

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23. Conf
    i
    gurations
    • Essentially named
    fi
    le collections
    
    • “implementation”, “api”, etc
    dependencies {
    implementation("com.squareup.moshi:moshi:1.13.0")
    testImplementation("junit:junit:4.13")
    }
    

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24. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    
    
    

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25. Conf
    i
    guration
    • Don’t confuse it with
    con
    fi
    gurations
    
    • The time spent from “go” to
    tasks actually executing
    

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26. Conf
    i
    guration
    

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27. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    
    
    

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28. Caching/Incremental Builds
    • Multiple kinds
    
    • build dir
    
    • Build cache
    
    • Local/Remote
    
    • Con
    fi
    guration cache
    
    • GRADLE_USER_HOME
    
    • Not Studio caches
    https://www.liutikas.net/2022/04/19/Caches-Everywhere.html
    

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29. Wiping Studio caches
    does not f
    i
    x your build
    

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30. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    

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31. Incremental Compilation (IC)
    • Multiple kinds
    
    • Java – Gradle – JavaCompile
    
    • Kotlin – JB/Google – KotlinCompile*
    
    • kaptGenerateStubs*Kotlin
    
    • kapt*Kotlin
    
    • compile*Kotlin
    
    • compile*JavaWithKotlinC
    

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32. Incremental Compilation (IC) – Java
    • Compilation avoidance
    
    • “Can we not run?”
    
    • ABI-based
    
    • Incremental Compilation
    
    • “Can we only recompile a subset?”
    https://blog.gradle.org/incremental-compiler-avoidance
    :project-a
    :project-b
    

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33. Incremental Compilation (IC) – Java
    • Compilation avoidance
    
    • “Can we not run?”
    
    • ABI-based
    
    • Incremental Compilation
    
    • “Can we only recompile a subset?”
    https://blog.gradle.org/incremental-compiler-avoidance
    :project-a
    :project-b
    

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34. Incremental Compilation (IC) – Java
    • Compilation avoidance
    
    • “Can we not run?”
    
    • ABI-based
    
    • Incremental Compilation
    
    • “Can we only recompile a subset?”
    https://blog.gradle.org/incremental-compiler-avoidance
    :project-a
    :project-b
    

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35. Incremental Compilation (IC) – Kotlin
    • Incremental only for now, no avoidance
    
    • Coming soon though!
    
    • Depends on producer-side IC data
    
    • This makes it tricky
    

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36. Incremental Compilation (IC) – Kotlin
    • Incremental only for now, no avoidance
    
    • Coming soon though!
    
    • Depends on producer-side IC data
    
    • This makes it tricky
    :project-a
    :project-b
    

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37. Incremental Compilation (IC) – Kotlin
    • Incremental only for now, no avoidance
    
    • Coming soon though!
    
    • Depends on producer-side IC data
    
    • This makes it tricky
    :project-a
    :project-b
    
    produces
    consumes
    

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38. Incremental Compilation (IC) – Kotlin
    • Incremental only for now, no avoidance
    
    • Coming soon though!
    
    • Depends on producer-side IC data
    
    • This makes it tricky
    :project-a
    :project-b
    
    produces
    consumes
    

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39. • Multiple kinds
    
    • Java – Gradle – JavaCompile
    
    • Kotlin – JB/Google – KotlinCompile*
    
    • kaptGenerateStubs*Kotlin
    
    • kapt*Kotlin
    
    • compile*Kotlin
    
    • compile*JavaWithKotlinC
    Incremental Compilation (IC) – Kotlin
    

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40. kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    Incremental Compilation (IC) – Kotlin
    

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41. kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    Incremental Compilation (IC) – Kotlin
    

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42. kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    Incremental Compilation (IC) – Kotlin
    

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43. kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    Incremental Compilation (IC) – Kotlin
    

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44. kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    Incremental Compilation (IC) – Kotlin
    

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45. compile*Kotlin
    Incremental Compilation (IC) – Kotlin
    

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46. compile*Kotlin
    Incremental Compilation (IC) – Kotlin
    KotlinCompile
    

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47. compile*Kotlin
    Incremental Compilation (IC) – Kotlin
    KotlinCompile
    kotlinc
    

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48. Incremental Compilation (IC) – Kotlin
    kotlinc
    Frontend Backend
    AnalysisHandler IR Lowering
    https://medium.com/google-developer-experts/crash-course-on-the-
    kotlin-compiler-1-frontend-parsing-phase-9898490d922b
    Parse/PSI
    psi2ir
    

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49. Incremental Compilation (IC) – Kotlin
    Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    

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50. Incremental Compilation (IC) – Kotlin
    Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    

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51. Incremental Compilation (IC) – Kotlin
    Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    

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52. Incremental Compilation (IC) – Kotlin
    Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    

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53. Incremental Compilation (IC) – Kotlin
    kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    

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54. Incremental Compilation (IC) – Kotlin
    Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    kaptGenerateStubs*Kotlin
    kapt*Kotlin
    compile*Kotlin compile*JavaWithKotlinC
    

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55. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    
    
    

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56. Daemons 😈
    Gradle Daemon Kotlin Daemon
    

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57. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    
    
    

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58. Annotation Processing
    javac/kapt KSP
    

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59. Annotation Processing
    • Non
    -
    incremental
    
    
    • Two types of incremental
    
    
    • ISOLATING (Dagger, Moshi, etc)
    
    
    • AGGREGATING (Glide)
    javac/kapt KSP
    

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60. Gradle Refresher
    • Tasks
    
    
    • Projects
    
    
    • Plugins
    
    
    • Conf
    i
    gurations
    
    
    • Conf
    i
    guration
    • Caching/Incremental
    Builds
    
    
    • Incremental
    Compilation (IC)
    
    
    • Daemons
    
    
    • Annotation Processing
    
    
    

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61. Things That Are Hurting Your Build
    

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62. Things That Are Hurting Your Build
    Things That Will Improve Your Build
    

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63. Things That Are Hurting Your Build
    Things That Will Improve Your Build
    Things That Will Keep Your Build
    Fast
    

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64. Things That Are Hurting Your Build
    

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65. Annotation Processors
    

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66. Annotation Processors
    

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67. Kapt
    • Minimum 3 compilation tasks
    
    
    • 4 if you generate/have Java sources (hi, Dagger!)
    
    
    • Brittle to classpath changes
    
    
    • Disables new FIR
    
    
    • Keeps appearing in later problems as a multiplier
    

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68. Frontend Backend
    AnalysisHandler IR Lowering
    Parse/PSI
    psi2ir
    

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69. Frontend
    Stub gen
    .java f
    i
    les
    

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70. kotlinc Frontend
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt f
    i
    les
    

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71. kotlinc
    

    (Frontend only)
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    

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72. kotlinc
    

    (Frontend only)
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    javac
    compileJava
    More
    

    .class f
    i
    les
    

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73. kotlinc
    

    (Frontend only)
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    javac
    compileJava
    More
    

    .class f
    i
    les
    

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74. KSP
    https://github.com/google/ksp
    

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75. kotlinc
    

    (Frontend only)
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    javac
    compileJava
    More
    

    .class f
    i
    les
    

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76. kotlinc
    

    (Frontend only)
    KSP
    .java/.kt
    
    
    f
    i
    les
    javac
    javaCompile
    More .class
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    

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77. kotlinc
    

    (Frontend only)
    KSP
    .kt
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    

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78. kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    all
    -
    open
    
    
    Kotlinx
    -
    serialization
    
    
    parcelize
    
    
    moshi
    
    
    etc.
    https://blog.bnorm.dev/writing-your-second-compiler-
    plugin-part-1
    

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79. kotlinc
    

    (Frontend only)
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    javac
    compileJava
    More
    

    .class f
    i
    les
    

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80. kotlinc
    

    (Frontend only)
    Stub gen
    .java f
    i
    les
    Kapt (javac)
    Kapt
    .java/.kt
    
    
    f
    i
    les
    kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    javac
    compileJava
    More
    

    .class f
    i
    les
    https://github.com/square/anvil
    
    
    

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81. kotlinc
    

    (Frontend and Backend)
    compileKotlin
    .class f
    i
    les
    Anvil runs here
    https://github.com/square/anvil
    
    
    

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82. buildSrc
    

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83. buildSrc
    • Regularly invalidates buildscript classpath
    
    
    • It’s like occasionally having
    - -
    rerun
    -
    tasks
    
    
    • What’s the alternative?
    
    
    • Version catalogs for deps
    
    
    • Separate repo + artifactory for plugins
    

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84. buildSrc
    • What about live testing?
    
    
    • Use included builds
    if ("slack.plugin.internal.localPath" in extra.properties) {
    val path = (extra["slack.plugin.internal.localPath"] as String)
    includeBuild(path) {
    dependencySubstitution {
    substitute(module("slack.internal.gradle:slack-plugin-internal"))
    .using(project(":slack-plugin-internal"))
    }
    }
    }
    

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85. ./gradlew clean
    

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86. ./gradlew clean
    

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87. Cleaning does not f
    i
    x
    your build
    

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88. Don’t mix IDE and
    command line builds
    

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89. Don’t mix IDE and
    command line builds
    https://issuetracker.google.com/
    issues/164145066
    

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90. View Slide

91. View Slide

92. “What do you think you’d produce if you were hammered?”

    – Chet, certi
    fi
    ed Gradle expert™
    

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93. Move NDK projects to a
    separate repo
    

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94. Gradle API Surface Area
    

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95. Gradle API Surface Area
    con
    fi
    gurations.all {
    }
    extensions.get(...)
    tasks.getByName(...)
    var property: String
    con
    fi
    gurations.con
    fi
    gureEach {
    // Lazy!
    }
    extensions.con
    fi
    gure(...) {
    // Lazy!
    }
    tasks.named(...) {
    // Lazy!
    }
    val property: Property
    http://autonomousapps.com/blog/rules-for-
    gradle-plugin-authors.html
    

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96. Incremental Compilation
    Issues
    https://www.zacsweers.dev/
    optimizing-your-kotlin-build/
    

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97. Incremental Compilation Issues
    • Pure Java projects break IC on every project that depends on them
    (directly or transitively)
    
    
    • Java
    -
    only, resources
    -
    only, etc
    
    
    • Workaround: add a Kotlin f
    i
    le
    
    
    • KT-30980 KT-38622
    
    
    • Code gen tools generating non
    -
    deterministic outputs
    
    
    • Resource ABI changes break IC (KT-40772)
    
    
    • Cleaning https://www.zacsweers.dev/
    optimizing-your-kotlin-build/
    

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98. Task Issues
    

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99. Identifying Task Issues
    

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100. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1
     

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101. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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102. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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103. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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104. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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105. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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106. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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107. Identifying Task Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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108. Identifying Caching
     Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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109. Identifying Caching
     Issues
     ./gradlew clean
     Build 1 Build 2
     

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110. Identifying Caching
     Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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111. Identifying Caching
     Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     

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112. Identifying Caching
     Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     🗂 Di
     ff
     erent directory
     

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113. Identifying Caching
     Issues
     ./gradlew :app:assembleDebug
     Build 1 Build 2
     ☁ CI
     

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114. Corporate Bloatware
     

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115. Literally bugs
     https://www.zacsweers.dev/
     optimizing-your-kotlin-build/
     

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116. Literally bugs
     • Kotlin build cache entries often break incremental
     compilation. KT-34862
     
     
     • Gradle AbstractCompile tasks (i.e. KotlinCompile) are
     sensitive to classpath jar ordering. gradle/gradle#15626
     
     
     • Error
     -
     prone freeCompilerArgs use. KT-41985
     https://www.zacsweers.dev/
     optimizing-your-kotlin-build/
     

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117. Old tools!
     

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118. Old tools
     • JDK
     
     
     • We are on 17, moving to 18
     
     
     • Kotlin
     
     
     • Gradle
     
     
     • Gradle plugins
     
     
     • Compiler plugins
     
     
     • Literally anything on your buildscript classpath
     

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119. Tune GCs
     org.gradle.jvmargs=... -XX:+UseG1GC \
     -XX:+UnlockExperimentalVMOptions \
     -XX:G1NewSizePercent=67 \
     -XX:G1MaxNewSizePercent=67
     https://github.com/slackhq/slack-gradle-plugin/blob/main/slack-
     plugin/src/main/kotlin/slack/gradle/tasks/BootstrapTask.kt
     

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120. Tune Daemons
     org.gradle.jvmargs=... -Xms2g -Xmx8g
     kotlin.daemon.jvmargs=... -Xms6g -Xmx24g
     https://github.com/slackhq/slack-gradle-plugin/blob/main/slack-
     plugin/src/main/kotlin/slack/gradle/tasks/BootstrapTask.kt
     

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121. (CI only)
     

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122. Don’t merge main on CI
     builds
     

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123. Lint memory usage
     

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124. Lint memory usage
     org.gradle.jvmargs=... -XX:MaxMetaspaceSize=1g
     

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125. Tune Daemons
     org.gradle.jvmargs=... -Xms24g -Xmx24g
     kotlin.daemon.jvmargs=... -Xms4g -Xmx4g
     https://github.com/slackhq/slack-gradle-plugin/blob/main/slack-
     plugin/src/main/kotlin/slack/gradle/tasks/BootstrapTask.kt
     

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126. Jacoco
     

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127. Jacoco
     

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128. Things That Are Hurting
     Your Build
     

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129. Things That Will Improve
     Your Build
     

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130. Build caching
     org.gradle.caching=true
     

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131. Remote Build
     
     
     caching
     buildCache {
     local {
     isEnabled = true
     }
     remote {
     isEnabled = !gradle.startParameter.isOf
     fl
     ine
     setUrl(“…”)
     // only write to cache from build server
     isPush = isCi
     credentials {
     username = ...
     password = ...
     }
     }
     }
     

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132. android
     -
     cache
     -
     f
     i
     x
     -
     gradle
     -
     plugin
     https://github.com/gradle/android-cache-
     fi
     x-gradle-plugin
     

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133. Virtual File System (VFS)
     org.gradle.vfs.watch=true
     https://blog.gradle.org/introducing-
     fi
     le-
     system-watching
     
     
     

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134. Conf
     i
     guration Caching
     org.gradle.unsafe.con
     fi
     guration-cache=true
     https://blog.gradle.org/introducing-
     con
     fi
     guration-caching
     

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135. Focus
     https://github.com/dropbox/focus
     ./gradlew :my-feature:sample:focus
     

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136. Single
     -
     variant Libraries
     androidComponents {
     beforeVariants(selector().withBuildType("debug")) { builder ->
     builder.enable = false
     }
     }
     

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137. Modularization
     

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138. Modularization 🔥
     

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139. Apple Silicon
     

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140. Non
     -
     transitive R classes
     

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141. Non
     -
     transitive R classes
     • 5.5MB or 8.5% of Slack APK size
     
     
     • 14% incremental build time improvement w/ layout change
     
     
     • import slack.l10n.R as L10nR
     

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142. Disable Android Features
     # Build features that are disabled by default in all projects
     android.defaults.buildfeatures.aidl=false
     android.defaults.buildfeatures.buildcon
     fi
     g=false
     android.defaults.buildfeatures.renderscript=false
     android.defaults.buildfeatures.resvalues=false
     android.defaults.buildfeatures.shaders=false
     

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143. Prefer JVM-only Projects
     

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144. Make A Platform Plugin
     import slack.gradle.Platforms
     plugins {
     id("slack.base")
     `java-platform`
     }
     val catalog = extensions.
     fi
     ndByType()
     ?.
     fi
     nd("libs")
     ?: error("Could not
     fi
     nd libs catalog!")
     Platforms.applyFromCatalog(project, catalog.get())
     https://github.com/slackhq/slack-gradle-plugin/blob/main/slack-
     plugin/src/main/kotlin/slack/gradle/Platforms.kt
     

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145. Other Things
     • Remove jetif
     i
     er (use `checkJetif
     i
     er` task in AGP 7.1)
     
     
     • api/impl projects
     
     
     • api/impl conf
     i
     gurations don’t avoid compilations, just
     control visibility
     
     
     •
     

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146. Things That Will Improve
     Your Build
     

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147. Things That Will Keep
     Your Build Fast
     

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148. Gradle Enterprise
     

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149. Gradle Enterprise
     • Remote build cache
     
     
     • Build scans
     
     
     • Compare builds
     
     
     • Trends/insight/visualization
     
     
     • Export API
     
     
     • Critical path
     
     
     • Tags/custom values
     
     
     • Debugging (everyone has a scan ready)
     

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150. Benchmarks
     https://github.com/gradle/gradle-pro
     fi
     ler
     

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151. Benchmarks
     

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152. Benchmarks
     

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153. Benchmarks
     

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154. Telemetry + Check
     -
     ins
     

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155. Telemetry
     • Local vs CI (GE tag)
     
     
     • System arch (rolling out M1 Macs)
     
     
     • Thermals
     
     
     • https:
     / /
     github.com/slackhq/slack
     -
     gradle
     -
     plugin/blob/main/slack
     -
     plugin/src/main/kotlin/slack/gradle/util/ThermalsWatcher.kt
     
     
     • VCS state
     
     
     • Env info (OS, version, etc)
     

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156. Gradle
     -
     doctor
     https://runningcode.github.io/gradle-doctor/
     

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157. TaskUpToDateValidator
     https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-main/buildSrc/
     private/src/main/kotlin/androidx/build/uptodatedness/TaskUpToDateValidator.kt
     

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158. modules
     -
     graph
     -
     assert
     https://github.com/jraska/modules-graph-assert
     

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159. modules
     -
     graph
     -
     assert
     https://github.com/jraska/modules-graph-assert
     moduleGraphAssert {
     maxHeight = 4
     allowed = [':.* -> :core', ':feature.* -> :lib.*'] // regex to match module names
     restricted = [':feature-[a-z]* -X> :forbidden-to-depend-on'] // regex to match module names
     con
     fi
     gurations = ['api', 'implementation'] // Dependency confs to look.
     }
     

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160. modules
     -
     graph
     -
     assert
     https://github.com/jraska/modules-graph-assert
     

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161. modules
     -
     graph
     -
     assert
     

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162. dependency
     -
     analysis
     -
     android
     -
     gradle
     -
     plugin
     https://github.com/autonomousapps/dependency-analysis-android-gradle-plugin
     

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163. dependency
     -
     analysis
     -
     android
     -
     gradle
     -
     plugin
     https://github.com/slackhq/slack-gradle-plugin/blob/main/slack-plugin/src/main/
     kotlin/slack/dependencyrake/DependencyRake.kt
     /**
     * Task that consumes the generated advice report json generated by `AdviceTask`
     * and applies its advice to the project build
     fi
     le. This is usually not run
     * directly, but rather added as a
     fi
     nalizer to the `AdviceTask` it reads from.
     */
     class RakeDependencies(...) : AbstractPostProcessingTask() {
     // ...
     }
     

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164. https://github.com/slackhq/slack-gradle-plugin/blob/main/slack-plugin/src/main/
     kotlin/slack/dependencyrake/DependencyRake.kt
     

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165. https://github.com/slackhq/slack-gradle-plugin
     Convention Plugins
     

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166. https://github.com/slackhq/slack-gradle-plugin
     Convention Plugins
     plugins {
     id("com.android.library")
     kotlin("android")
     id("com.squareup.anvil")
     }
     android {
     namespace = "slack.libraries.emoji.api"
     compileSdk = 31
     defaultCon
     fi
     g {
     minSdk = 26
     }
     buildTypes {
     debug {
     matchingFallbacks.add("release")
     }
     }
     compileOptions {
     sourceCompatibility = JavaVersion.VERSION_1_8
     targetCompatibility = JavaVersion.VERSION_1_8
     }
     }
     androidComponents {
     beforeVariants { builder ->
     if (builder.buildType == "debug") {
     builder.enable = false
     } else {
     builder.enableAndroidTest = hasProperty("slack.libraryWithAndroidTest")
     }
     }
     }
     anvil {
     generateFactories = true
     }
     dependencies {
     compileOnly(libs.dagger.dagger)
     implementation(projects.libraries.emoji.data)
     implementation(projects.libraries.foundation.slackCommons.android)
     implementation(projects.libraries.imageLoading)
     implementation(projects.libraries.model)
     implementation(projects.libraries.telemetry.telemetryPublic)
     implementation(libs.rxJava.java3)
     }
     

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167. https://github.com/slackhq/slack-gradle-plugin
     Convention Plugins
     plugins {
     id("slack.base")
     id("com.android.library")
     kotlin("android")
     }
     slack {
     features {
     dagger()
     }
     }
     dependencies {
     implementation(projects.libraries.emoji.data)
     implementation(projects.libraries.foundation.slackCommons.android)
     implementation(projects.libraries.imageLoading)
     implementation(projects.libraries.model)
     implementation(projects.libraries.telemetry.telemetryPublic)
     implementation(libs.rxJava.java3)
     }
     

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168. Future
     https://slack.engineering/shadow-jobs/
     

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169. Future
     New Kotlin IC
     • Consumer
     -
     side IC based on classpath snapshot
     
     
     • Unstable preview available in 1.6.20, targeting 1.7
     
     
     • Solves many producer
     -
     side issues (Java projects,
     caching, etc)
     
     
     • True compilation avoidance in some cases (
     ! !
     )
     kotlin.incremental.useClasspathSnapshot=true
     https://youtrack.jetbrains.com/issue/KT-45777
     

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170. Future
     New Kotlin IC
     https://youtrack.jetbrains.com/issue/
     KT-45777#focus=Comments-27-6004789.0-0
     

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171. Future
     New Kotlin IC
     

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172. Future
     New Kotlin IC
     

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173. Future
     K2 Compiler
     • New Kotlin compiler frontend (aka FIR)
     
     
     • Promises 2-4x build speed improvements
     
     
     • Preview coming in 1.7
     https://blog.jetbrains.com/kotlin/2021/10/the-road-to-the-k2-compiler/
     

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174. Future
     Conf
     i
     guration Caching
     org.gradle.unsafe.con
     fi
     guration-cache=true
     https://blog.gradle.org/introducing-
     con
     fi
     guration-caching
     

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175. Future
     Gradle Project Isolation
     • Conf
     i
     guration cache pt. 2
     
     
     • True project isolation, will allow parallel
     conf
     i
     guration and tooling model creation (aka Studio
     sync)
     
     
     • WIP. TL;DR don’t use allprojects/subprojects
     https://gradle.github.io/con
     fi
     guration-cache/#project_isolation
     systemProp.org.gradle.unsafe.isolated-projects=true
     

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176. –You, an upstanding citizen
     “How can I help?”
     

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177. How can I help?
     • Report bugs!
     
     
     • Open source your build stuff
     
     
     • Test/prepare for new features
     
     
     • Use modern APIs
     
     
     • Make your own convention plugin
     
     
     • File feature requests
     *
     

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178. –You, an upstanding citizen
     “What should I do today?”
     

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179. What should I do today?
     • Audit deprecated/eager APIs
     
     
     • Update your tools (JDK, Gradle, Kotlin, etc)
     
     
     • Swap KSP for kapt where possible
     
     
     • Single
     -
     variant libraries
     
     
     • Disable android features by default
     
     
     • Fix java
     -
     only projects breaking IC
     
     
     • Dependency analysis to remove unused deps
     

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180. –You, a future upstanding citizen
     “What should I do tomorrow?”
     

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181. What should I do tomorrow?
     • Learn some Gradle
     
     
     • Reduce/remove Kapt
     
     
     • Create gradle
     -
     prof
     i
     ler
     scenarios
     
     
     • Modularization
     
     
     • Gradle Enterprise
     
     
     • Apple Silicon
     • Incorporate new tools prep
     in planning
     
     
     • OSS your stuff
     

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182. People to follow for more!
     • Tony Robalik – @AutonomousApps – https:
     / /
     dev.to/autonomousapps
     
     
     • Aurimas Liutikas – @_aurimas – https:
     / / w w w
     .liutikas.net/blog
     -
     posts
     
     
     • Iñaki Villar – @inyaki_mwc
     
     
     • Ryan Harter – @rharter – http:
     / /
     ryanharter.com/
     
     
     • Xavier Ducrohet – @droidxav – https:
     / /
     developer.android.com/reference/tools/gradle
     -
     api
     
     
     • “Xav says read the docs and stop touching internal APIs”
     
     
     • Ivan Gavrilovic – @gavra0
     
     
     • Cesar Puerta – @CesarDielo
     
     
     • Nelson Osacky – @nellyspageli – https:
     / /
     osacky.com/
     
     
     • Jendrik Johannes – @jeoj – youtube.com/c/onepieceSoftware – github.com/jjohannes
     

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183. Zac Sweers – Slack – @ZacSweers
     Improve Build Times in
     Less Time
     

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