--- rpm-4.15.1/rpmbuild.c~	2019-06-26 16:17:31.000000000 +0200
+++ rpm-4.15.1/rpmbuild.c	2020-01-13 23:29:36.442259031 +0100
@@ -435,13 +435,6 @@
     if (ba->buildRootOverride)
 	buildRootURL = rpmGenPath(NULL, ba->buildRootOverride, NULL);
 
-    /* Create build tree if necessary */
-    const char * buildtree = "%{_topdir}:%{_specdir}:%{_sourcedir}:%{_builddir}:%{_rpmdir}:%{_srcrpmdir}:%{_buildrootdir}";
-    const char * rootdir = rpmtsRootDir(ts);
-    if (rpmMkdirs(!rstreq(rootdir, "/") ? rootdir : NULL , buildtree)) {
-	goto exit;
-    }
-
     if (buildMode == 't') {
     	char *srcdir = NULL, *dir;
 
@@ -508,6 +501,13 @@
 	goto exit;
     }
 
+    /* Create build tree if necessary */
+    const char * buildtree = "%{_topdir}:%{_specdir}:%{_sourcedir}:%{_builddir}:%{_rpmdir}:%{_srcrpmdir}:%{_buildrootdir}";
+    const char * rootdir = rpmtsRootDir(ts);
+    if (rpmMkdirs(!rstreq(rootdir, "/") ? rootdir : NULL , buildtree)) {
+	goto exit;
+    }
+
     if ((rc = rpmSpecBuild(ts, spec, ba))) {
 	goto exit;
     }