Recently I updated Android studio to version 1.3, and then it fails gradle sync. Error message is something like,
Error:(30, 13) Failed to resolve: com.squareup.picasso:picasso:2.5.2 Show in File Show in Project Structure dialog
It seems that https proxy server was not working correctly, even if I’m setting proxy server in [File] → [Settings…] → [Appearance & Behavior] → [HTTP Proxy].
Solution
You can set http proxy server & https proxy server manually in gradle.properties file. Add below to your gradle.properties (Project Properties) file.
systemProp.http.proxyHost=xxx.xxx.xxx.xxx systemProp.http.proxyPort=8080 systemProp.https.proxyHost=xxx.xxx.xxx.xxx systemProp.https.proxyPort=8080
Replace xxx.xxx.xxx.xxx with IP address of your proxy server & 8080 with your proxy’s port number.
After that, try [Build] → [Clean Project] to re-execute Gradle Sync.