Resolves the following error.
Similar to libguestfs commit 489b14b75e5f30010d8a8c8d3a10ecc52b629563

/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /usr/lib64/ocaml/guestfs/libmlguestfs.a(libguestfsocaml_a-guestfs-c.o): in function `guestfs_finalize':
/home/abuild/rpmbuild/BUILD/libguestfs-1.44.2/ocaml/guestfs-c.c:86: undefined reference to `rpl_free'
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /home/abuild/rpmbuild/BUILD/libguestfs-1.44.2/ocaml/guestfs-c.c:88: undefined reference to `rpl_free'
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /usr/lib64/ocaml/guestfs/libmlguestfs.a(libguestfsocaml_a-guestfs-c.o): in function `guestfs_int_ocaml_set_event_callback':
/home/abuild/rpmbuild/BUILD/libguestfs-1.44.2/ocaml/guestfs-c.c:239: undefined reference to `rpl_free'
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /usr/lib64/ocaml/guestfs/libmlguestfs.a(libguestfsocaml_a-guestfs-c.o): in function `guestfs_int_ocaml_delete_event_callback':
/home/abuild/rpmbuild/BUILD/libguestfs-1.44.2/ocaml/guestfs-c.c:266: undefined reference to `rpl_free'
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /usr/lib64/ocaml/guestfs/libmlguestfs.a(libguestfsocaml_a-guestfs-c.o): in function `guestfs_int_ocaml_event_to_string':
/home/abuild/rpmbuild/BUILD/libguestfs-1.44.2/ocaml/guestfs-c.c:290: undefined reference to `rpl_free'
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /usr/lib64/ocaml/guestfs/libmlguestfs.a(libguestfsocaml_a-guestfs-c-actions.o):/home/abuild/rpmbuild/BUILD/libguestfs-1.44.2/ocaml/guestfs-c-actions.c:1188: more undefined references to `rpl_free' follow
collect2: error: ld returned 1 exit status
File "caml_startup", line 1:
Error: Error during linking


Index: virt-v2v-1.44.0/gnulib/lib/free.c
===================================================================
--- /dev/null
+++ virt-v2v-1.44.0/gnulib/lib/free.c
@@ -0,0 +1,53 @@
+/* Make free() preserve errno.
+
+   Copyright (C) 2003, 2006, 2009-2021 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* written by Paul Eggert */
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdlib.h>
+
+/* A function definition is only needed if HAVE_FREE_POSIX is not defined.  */
+#if !HAVE_FREE_POSIX
+
+# include <errno.h>
+
+void
+rpl_free (void *p)
+# undef free
+{
+# if defined __GNUC__ && !defined __clang__
+  /* An invalid GCC optimization
+     <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98396>
+     would optimize away the assignments in the code below, when link-time
+     optimization (LTO) is enabled.  Make the code more complicated, so that
+     GCC does not grok how to optimize it.  */
+  int err[2];
+  err[0] = errno;
+  err[1] = errno;
+  errno = 0;
+  free (p);
+  errno = err[errno == 0];
+# else
+  int err = errno;
+  free (p);
+  errno = err;
+# endif
+}
+
+#endif
Index: virt-v2v-1.44.0/gnulib/lib/Makefile.am
===================================================================
--- virt-v2v-1.44.0.orig/gnulib/lib/Makefile.am
+++ virt-v2v-1.44.0/gnulib/lib/Makefile.am
@@ -35,7 +35,8 @@ libgnu_la_SOURCES = \
 	xstrtoll.c \
 	xstrtoul.c \
 	xstrtoull.c \
-	xstrtoumax.c
+	xstrtoumax.c \
+	free.c
 libutils_la_CFLAGS = \
 	$(WARN_CFLAGS) $(WERROR_CFLAGS) \
 	$(GCC_VISIBILITY_HIDDEN)