To set a proxy, you can add arguments in gradlew:
./gradlew goBuild -DsocksProxyHost=127.0.0.1 -DsocksProxyPort=1080
And it is the same for other gradlew command.
Also, you can persist the arguments via ~/.gradle/gradle.properties or ${projectRoot}/gradle.properties:
org.gradle.jvmargs=-DsocksProxyHost=127.0.0.1 -DsocksProxyPort=1080
And HTTP proxy:
-Dhttp.proxyHost=<host> -Dhttp.proxyPort=<port>
And HTTPS proxy:
-Dhttps.proxyHost=<host> -Dhttps.proxyPort=<port>
To learn more about environment and proxy, see Gradle environment and Java proxy
NOTE this only sets proxy for Gogradle process, not for git and hg. If you want to set proxy for git and hg, please visit Getting git to work with a proxy server and using hg through a proxy