Added check for nil-pointer panic

Author: cmaglie

commands/commands_test.go

@@ -493,8 +493,13 @@ func TestCompileCommands(t *testing.T) {
 	require.Zero(t, exitCode, "exit code")
 	require.Contains(t, string(d), "Sketch created")
 
-	// Build sketch for arduino:avr:uno
+	// Build sketch without FQBN
 	test1 := currSketchbookDir.Join("Test1").String()
+	exitCode, d = executeWithArgs(t, "compile", test1)
+	require.NotZero(t, exitCode, "exit code")
+	require.Contains(t, string(d), "No Fully Qualified Board Name provided")
+
+	// Build sketch for arduino:avr:uno
 	exitCode, d = executeWithArgs(t, "compile", "-b", "arduino:avr:uno", test1)
 	require.Zero(t, exitCode, "exit code")
 	require.Contains(t, string(d), "Sketch uses")

commands/compile/compile.go

@@ -31,7 +31,7 @@ import (
 	"github.com/arduino/arduino-cli/commands"
 	"github.com/arduino/arduino-cli/commands/core"
 	"github.com/arduino/arduino-cli/common/formatter"
-	"github.com/arduino/go-paths-helper"
+	paths "github.com/arduino/go-paths-helper"
 	properties "github.com/arduino/go-properties-orderedmap"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -109,7 +109,7 @@ func run(cmd *cobra.Command, args []string) {
 		os.Exit(commands.ErrGeneric)
 	}
 
-	if flags.fqbn == "" && sketch != nil {
+	if flags.fqbn == "" && sketch != nil && sketch.Metadata != nil {
 		flags.fqbn = sketch.Metadata.CPU.Fqbn
 	}
 	if flags.fqbn == "" {