Dependency error when using aar library

Question

I have a module with a .aar file in libs folder. I used the solution posted here [1]: http://kevinpelgrims.com/blog/2014/05/18/reference-a-local-aar-in-your-android-project/ to add the .aar file as dependency and was able to compile the module properly.

Now I want to use this module as a dependency to the main module in my project and compile. However when i try to compile, i do see an error which says that gradle was not able to find the particular .aar file. why would my main module not find a file which is in the libs folder of my sub module. Was wondering if anyone came across this issue.

my project structure is like this

--mainmodule
  --build.gradle (submodule as a dependency)
--submodule
   --libs
      -- abc.aar

Here is the error gradle throws: When unzipping library ':abc:, either group, name or version is empty

Answer 1

If I understand your problem right and you've followed the steps described in the link you shared, then adding this to your mainmodule's build.gradle should do the job:

flatDir {
    dirs "../submodule/libs"
}

You basically have the same issue that you fixed in your submodule, since the mainmodule is struggling to resolve transitive dependencies (abc.aar) of submodule.

Recommended way:

While the answer above should fix your issue, Android Studio supports a better way to do this. Import a local aar file via the File>New>New Module>Import .JAR/.AAR Package option in Android Studio v1.3+. You can then have your submodule depend on that aar-module as follows:

dependencies {
    compile project(':aar-module')
}