The timestamps are more than 50,000 seconds ago

Which timestamps are you referring to? The ones I see in the snippet above are from 3~ hours ago:

t, err := time.Parse(time.RFC3339, "2020-04-10T16:39:15Z")
if err != nil { panic(err) }
fmt.Println(time.Since(t))
// Output: 3h5m32.054424s

For context, aix-ppc64 is a reverse builder (meaning it's run externally and connects to the coordinator to ask for work; it's not managed by the coordinator) and there is only one instance. The coordinator was redeployed 3.5 hours ago (farmer.golang.org displays "Uptime 3h35m55s."). It seems https://farmer.golang.org/try?commit=37ab01eb was the first trybot run that picked up the aix-ppc64 builder, but the builder is stuck on:

Building Go cmd/dist using /opt/freeware/lib/golang. (go1.13 aix/ppc64)
Building Go toolchain1 using /opt/freeware/lib/golang.
Building Go bootstrap cmd/go (go_bootstrap) using Go toolchain1.
Building Go toolchain2 using go_bootstrap and Go toolchain1.

It might be worth canceling that trybot run (by deleting the Run-TryBot+1 vote) and letting it try again, perhaps the next time it won't get stuck. But if that doesn't help, then there must be something up with the builder.

/cc @trex58

I'm sorry, you're right, I did misread the timestamps. I'll close this issue.

Again, it gets stuck in the same place.
https://farmer.golang.org/try?commit=efd5d44c