https://bugs.gentoo.org/659840
--- a/port/cpl_vsil_curl.cpp
+++ b/port/cpl_vsil_curl.cpp
@@ -8617,8 +8617,10 @@
         if( poFSHandler )
             poFSHandler->ClearCache();
     }
-
+#if !defined(HAVE_CURL) || defined(CPL_MULTIPROC_STUB)
+#else
     VSICurlStreamingClearCache();
+#endif
 }
 
 #endif /* HAVE_CURL */