Pulumi previews on our CI server have started failing with "Program exited with non-zero exit code: -1" error. The previews from our laptop work fine. I see this bit with verbose logging, but can't tell what is happening.

I0131 17:48:57.226729     203 log.go:81] eventSink::Infoerr(<{%reset%}>I0131 17:48:57.226668     216 log.go:81] Explicitly ignoring and discarding error: sync /dev/stdout: invalid argument
<{%reset%}>)
I0131 17:48:57.226754     203 log.go:81] eventSink::Infoerr(<{%reset%}>I0131 17:48:57.226712     216 log.go:81] Explicitly ignoring and discarding error: sync /dev/stderr: invalid argument
<{%reset%}>)
    pulumi:pulumi:Stack my-project-my-stack running I0131 17:48:57.226668     216 log.go:81] Explicitly ignoring and discarding error: sync /dev/stdout: invalid argument
    pulumi:pulumi:Stack my-project-my-stack running I0131 17:48:57.226712     216 log.go:81] Explicitly ignoring and discarding error: sync /dev/stderr: invalid argument
I0131 17:48:57.227190     203 log.go:81] langhost[nodejs].Run(pwd=/drone/src/client/ingress,program=.,...,dryrun=true) success: progerr=Program exited with non-zero exit code: -1, bail=false
I0131 17:48:57.227246     203 log.go:81] EvalSourceIterator ended with an error: an unhandled error occurred: Program exited with non-zero exit code: -1
I0131 17:48:57.227270     203 log.go:81] deploymentExecutor.Execute(...): incoming event (nil? true, an unhandled error occurred: Program exited with non-zero exit code: -1)
I0131 17:48:57.227286     203 log.go:81] eventSink::Error(<{%reset%}>an unhandled error occurred: Program exited with non-zero exit code: -1<{%reset%}>)
    pulumi:pulumi:Stack my-project-my-stack running error: an unhandled error occurred: Program exited with non-zero exit code: -1
I0131 17:48:57.227312     203 log.go:81] StepExecutor worker(-1): StepExecutor.waitForCompletion(): waiting for worker threads to exit

Has anyone seen this before? This started today and can consistently reproduce it.