Gradle build failed to resolve aar library dependency (trnql sdk)

Question

When I attempt to build my project using gradle, I get the following error:

Failed to resolve: com.trnql:lib-release 1.0.0

It seems it cannot find the android archive file (aar) that is in the libs folder. The dependencies section of the build.gradle file looks like this:

And the project structure looks like this:

The aar file is valid, it is just not resolved by the build system. What can I do to fix this problem?

Answer 1

The problem here is that gradle will try to find this aar in one of the declared repository. The libs directory is not a repository... BUT you can declare it like this :

repositories {
    mavenCentral()
    flatDir {
        dirs 'libs'
    }
}

and gradle will find it.

Answer 2

When you create a new Android studio project, your top level build.gradle will have a buildscript and an allproject part (see below), and if you insert the

flatDir {
            dirs 'libs'
        }

part into the buildscript's repositories, it won't work.
You have to paste it into the allprojects' repositories, like here:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.3'
    }
}

allprojects {
    repositories {
        jcenter()
        flatDir {
            dirs 'libs'
        }
    }
}

Answer 3

In my case, in my library module my build.gradle looked something like:

buildscript {
    repositories {
        flatDir {
            dirs "libs"
        }
    }
}

I had to remove the buildscript bit so that it looked like this in the end:

repositories {
    flatDir {
        dirs "libs"
    }
}

Then it was able to sync and, thereafter, build.

Answer 4

And to be complete as possible: Lets say you want your AAR's in another directory in a sub-module....

Then in your TOP LEVEL project's build.gradle file, you would do the following:

buildscript {
    // stuff here
}
allprojects {
    repositories {
        // all your standard  stuff, jcenter, maven, etc
        flatDir {
            dirs project(':MY_MODULE_NAME').file('MODULE_SUB_DIRECTORY')
        }
    }
}

If your module directory layout looked like this:

MyFancyModule/
  /aars         <-- aar files go here
  /build
  /libs         <-- jar files go here
  /src
  build.gradle   <-- this is NOT your top level gradle file

Then the line in your TOP LEVEL GRADLE FILE would look like:

dirs project(':MyFancyModule').file('aars')

Answer 5

put your aar file in libs dir, then modify part of your build.gradle file like below, the difference is that you missed *.aar when compile fileTree

repositories {
    flatDir {
        dirs 'libs'
    }
}

compile fileTree(dir:'libs', include:['*.jar', '*.aar'])

Answer 6

The dependency needs to be at the top of the list of dependencies.

compile 'com.trnql:lib-release:1.0.0@aar' goes to the top of the list just under "compile fileTree..."