My build.gradle look's like this:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath group: 'org.gradlefx', name: 'gradlefx', version: '0.6'
    }
}

apply plugin: 'gradlefx'
flexHome = "/Users/mordesku/Applications/AdobeAIRSDK"
version = '1.0-SNAPSHOT'
type = 'air'

repositories {
        mavenCentral()
    mavenRepo name: 'yoolab-releases',      url: "http://projects.yoolab.org/maven/content/repositories/releases"
        maven {
            name 'xxx-artifactory'
            credentials {
                username 'xxxx'
                password 'xxxx'
            }
            url "http://xxx.xxx.pl/artifactory/plugins-release-local"
        }
        
}

//dependency versions
ext.as3commons_lang_version = '0.3.2'

dependencies {
    merged group: 'org.as3commons', name: 'as3commons-lang', version: as3commons_lang_version, ext: 'swc'
//        airSDK  group: 'com.adobe', name: 'AdobeAIRSDK', version: '3.5', ext: 'zip'
}

air {
    storepass = 'xxxx'
    includeFileTrees = [fileTree(dir: 'src/main/flex/', include: 'assets/appIcon.png')]
}

When building I got that error:

jablecznik:builder mordesku$ gradle build

FAILURE: Build failed with an exception.

* What went wrong:
Error: 
[The path to the Flex home directory isn't valid (/Users/mordesku/Applications/AdobeAIRSDK): can't find 'flex-config.xml' at '/frameworks/flex-config.xml']

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 5.37 secs

But i got valid AirSDK 3.5