The cmd/go tests involving git requests to external services (mainly golang.org, github.com, gopkg.in) are expected to have a slightly nonzero failure rate due to external service outages. However, the failure rate on the linux-386-longtest builder in particular seems to have increased significantly starting in September, without a corresponding increase in the failure rate on the linux-amd64-longtest builder, and many of the failures are to the Go project's own Git server (go.googlesource.com).
It isn't clear to me whether these failures are due to network drops, or perhaps bugs in the builder's git implementation causing the upstream git server to drop the connection.
@golang/release, were there any builder image or configuration changes around September that might explain the increase in failure rate? Could we talk with the go.googlesource.com admins about whether they have also seen a higher error rate on the server side in the same timeframe?
greplogs --dashboard -md -l -e 'fatal: The remote end hung up unexpectedly' --since=2021-01-01