If you haven't run into :beam-sdks-go:buildLinuxAmd64 or similar failing with "undefined: passert.Sum" recently, stop reading now.
The root cause is that the gogradle plugin doesn't clean up the vendor directories <https://golang.org/cmd/go/#hdr-Vendor_Directories> that it sets up, in combination with trying to use gradle with Go, leads to gradle vendoring the beam package in the sdks/go/test, sdks/go/examples, sdks/go/container directories. This vendoring is persistent on the local client, and isn't cleaned up by the clean task. The immediate fix is to navigate to each of the sdks/go, and sdks/go/{test|examples|container} directories and delete the vendor and .gogradle directories. eg Run the following from your beam git root, if your'e using a *Unix or similar: rm -rf sdks/go/{vendor,.gogradle} sdks/go/{test,examples,container}/{vendor,.gogradle} Then try running your gradle command again. Go gradle will create the same vendored directories, but will at least have a more up to date version of the Go SDK. The short term fix would be to fix the recursive clean tasks that affect the go builds to also remove the vendor directories, if not targetting the vendored copy of beam specifically. This situation is awful and while the long term fix would probably be to use Go Modules <https://github.com/golang/go/wiki/Modules> directly (see BEAM-5379 <https://issues.apache.org/jira/browse/BEAM-5379>), and replace gogradle plugin with targeted bash scripts, allowing the go tool to manage dependencies and build artifacts directly. If you're familiar with gradle and could provide guidance on customizing a task, so it's properly invoked on the general clean task, it would be much appreciated. BEAM-5465 <https://issues.apache.org/jira/browse/BEAM-5465> has been filed to track that work. Thank you for your patience, Robert B