Disable interactive progress display when no terminal size is available (#3936)

It appears there are cases where our IsInteractive heuristics return true, but terminal.GetSize returns an error. In these cases, we should assume we do not have an interactive terminal and avoid trying to render interactive progress by default.

Fixes #3935.

CHANGELOG.md

@@ -20,6 +20,9 @@ CHANGELOG
 - Support exporting older stack versions.
   [#3906](https://github.com/pulumi/pulumi/pull/3906)
 
+- Disable interactive progress display when no terminal size is available.
+  [#3936](https://github.com/pulumi/pulumi/pull/3936)
+
 ## 1.10.1 (2020-02-06)
 - Support stack references in the Go SDK.
   [#3829](https://github.com/pulumi/pulumi/pull/3829)

pkg/backend/display/progress.go

@@ -272,10 +272,15 @@ func ShowProgressEvents(op string, action apitype.UpdateKind, stack tokens.QName
 	}
 
 	terminalWidth, terminalHeight, err := terminal.GetSize(int(os.Stdout.Fd()))
-	contract.IgnoreError(err)
-	display.isTerminal = opts.IsInteractive
-	display.terminalWidth = terminalWidth
-	display.terminalHeight = terminalHeight
+	if err == nil {
+		// If the terminal has a size, use it.
+		display.isTerminal = opts.IsInteractive
+		display.terminalWidth = terminalWidth
+		display.terminalHeight = terminalHeight
+	} else {
+		// Else assume we are not displaying in a terminal.
+		display.isTerminal = false
+	}
 
 	go func() {
 		display.processEvents(ticker, events)