diff --git a/runner/cmd.go b/runner/cmd.go
index dcf933cad0a61d8fa450395a504f7223003f26fa_cnVubmVyL2NtZC5nbw==..659de86e0598b60c975a9ea2c29bb813a7e9b076_cnVubmVyL2NtZC5nbw== 100644
--- a/runner/cmd.go
+++ b/runner/cmd.go
@@ -1,9 +1,11 @@
 package runner
 
 import (
+	"fmt"
+
 	"github.com/go-cmd/cmd"
 )
 
 func RunCMD(c *cmd.Cmd) (err error, stdout, stderr []string) {
 	statusChan := c.Start()
 	status := <-statusChan
@@ -4,11 +6,11 @@
 	"github.com/go-cmd/cmd"
 )
 
 func RunCMD(c *cmd.Cmd) (err error, stdout, stderr []string) {
 	statusChan := c.Start()
 	status := <-statusChan
-	if status.Error != nil {
-		return err, status.Stdout, status.Stderr
+	if status.Error != nil || status.Exit > 0 {
+		return fmt.Errorf("Cannot execute command: %w", err), status.Stdout, status.Stderr
 	}
 	stdout = status.Stdout
 	stderr = status.Stderr
diff --git a/runner/main.go b/runner/main.go
index dcf933cad0a61d8fa450395a504f7223003f26fa_cnVubmVyL21haW4uZ28=..659de86e0598b60c975a9ea2c29bb813a7e9b076_cnVubmVyL21haW4uZ28= 100644
--- a/runner/main.go
+++ b/runner/main.go
@@ -67,6 +67,9 @@
 					Str("stderr", strings.Join(stdErr, "\n")).
 					Msg("failed to run command")
 
+				// TODO: print error to stderr
+				// Error must be pretty printed to end users /!\
+				fmt.Printf("\n%s\n\n", strings.Join(stdErr, "\n"))
 				return fmt.Errorf("failed to run command: %w", err)
 			}
 			if tmpFile, err := ioutil.TempFile(tmpDir, fmt.Sprintf("compiled-%s-", name)); err != nil {
@@ -101,6 +104,9 @@
 			Str("stderr", strings.Join(stdErr, "\n")).
 			Msg("failed to run command")
 
+		// TODO: print error to stderr
+		// Error message must be pretty printed to end users
+		fmt.Printf("\n%s\n\n", strings.Join(stdErr, "\n"))
 		return fmt.Errorf("failed to run command: %w", err)
 	}
 	if tmpFile, err := ioutil.TempFile(tmpDir, "fully-compiled-"); err != nil {