Bug: https://bugs.gentoo.org/894320
--- a/src/common.h
+++ b/src/common.h
@@ -35,6 +35,7 @@
 
 /* Tracing, useful in debugging, but not officially supported. */
 #ifdef ENABLE_TRACING
+#include "main.h" /* Needed for info */
 #define Trace(x) info x
 #else
 #define Trace(x)
--- a/src/main.h
+++ b/src/main.h
@@ -20,6 +20,7 @@
   along with lbzip2.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#pragma once
 #include <limits.h>             /* CHAR_BIT */
 
 #if 8 != CHAR_BIT