diff --git a/src/driver/tpax_driver_ctx.c b/src/driver/tpax_driver_ctx.c
index 4348ebc..b7b949e 100644
--- a/src/driver/tpax_driver_ctx.c
+++ b/src/driver/tpax_driver_ctx.c
@@ -55,6 +55,9 @@ static const struct tpax_fd_ctx tpax_default_fdctx = {
 	.fdlog = (-1),
 };
 
+/* fallback error description */
+static const char tpax_null_errdesc[] = "<no error description>";
+
 struct tpax_driver_ctx_alloc {
 	struct argv_meta *		meta;
 	struct tpax_driver_ctx_impl	ctx;
@@ -78,6 +81,21 @@ static uint32_t tpax_argv_flags(uint32_t flags)
 	return ret;
 }
 
+static const char * tpax_driver_errdesc(void)
+{
+	int             lerrno;
+	const char *    errstr;
+
+	lerrno = errno;
+	errno  = 0;
+
+	errstr = strerror(lerrno);
+	errstr = errno ? tpax_null_errdesc : errstr;
+	errno  = lerrno;
+
+	return errstr;
+}
+
 static int tpax_driver_usage(
 	int				fdout,
 	const char *			program,
@@ -173,8 +191,7 @@ static int tpax_driver_usage_copy_mode(
 			break;
 
 		default:
-			if (!(errdesc = strerror(errno)))
-				errdesc = "<no error description>";
+			errdesc = tpax_driver_errdesc();
 
 			tpax_dprintf(
 				fdout,
@@ -263,15 +280,7 @@ static int tpax_driver_error_archive_path(
 	struct argv_meta *		meta,
 	bool                            fwrite)
 {
-	int             lerrno;
-	const char *    errstr;
-
-	lerrno = errno;
-	errno  = 0;
-
-	errstr = strerror(lerrno);
-	errstr = errno ? "" : errstr;
-	errno  = lerrno;
+	const char * errstr = tpax_driver_errdesc();
 
 	if (fwrite) {
 		tpax_dprintf(
@@ -584,15 +593,7 @@ static int tpax_driver_srcstat_error(
 	const struct argv_entry *       archive,
 	const char *                    program)
 {
-	int             lerrno;
-	const char *    errstr;
-
-	lerrno = errno;
-	errno  = 0;
-
-	errstr = strerror(lerrno);
-	errstr = errno ? "" : errstr;
-	errno  = lerrno;
+	const char * errstr = tpax_driver_errdesc();
 
 	if (archive) {
 		tpax_dprintf(
@@ -615,15 +616,7 @@ static int tpax_driver_cache_error(
 	struct tpax_driver_ctx_impl *   ctx,
 	const char *                    program)
 {
-	int             lerrno;
-	const char *    errstr;
-
-	lerrno = errno;
-	errno  = 0;
-
-	errstr = strerror(lerrno);
-	errstr = errno ? tpax_null_errdesc : errstr;
-	errno  = lerrno;
+	const char * errstr = tpax_driver_errdesc();
 
 	tpax_dprintf(
 		ctx->fdctx.fderr,