From 802350f8dafebf9c8e674f92bc43816fc21f7081 Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Sat, 29 Sep 2018 22:39:44 +0200
Subject: [PATCH] main: helpful error message for flash cmd without -target

---
 main.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/main.go b/main.go
index 9137bc3f..25b43d11 100644
--- a/main.go
+++ b/main.go
@@ -181,6 +181,10 @@ func Flash(pkgName, target, port string, printIR, dumpSSA, debug bool, printSize
 	}
 
 	return Compile(pkgName, ".hex", spec, printIR, dumpSSA, debug, printSizes, func(tmppath string) error {
+		if spec.Flasher == "" {
+			return errors.New("no flash command specified - did you miss a -target flag?")
+		}
+
 		// Create the command.
 		flashCmd := spec.Flasher
 		flashCmd = strings.Replace(flashCmd, "{hex}", tmppath, -1)