Add -gc patch to fix FTBFS with OCaml 4.10.

ocaml-base-gc.patch

@@ -0,0 +1,15 @@
+--- a/src/exn_stubs.c
++++ b/src/exn_stubs.c
+@@ -1,7 +1,12 @@
+ #include <caml/mlvalues.h>
++#include <caml/version.h>
++
++#if OCAML_VERSION < 41000
+ 
+ extern int caml_backtrace_pos;
+ 
++#endif
++
+ CAMLprim value Base_clear_caml_backtrace_pos () {
+   caml_backtrace_pos = 0;
+   return Val_unit;

ocaml-base.spec

@@ -17,6 +17,9 @@ Summary:        Jane Street standard library for OCaml
 License:        MIT
 URL:            https://github.com/janestreet/%{srcname}
 Source0:        %{url}/archive/v%{version}/%{srcname}-%{version}.tar.gz
+# Fix failure to build with ocaml 4.10
+# https://github.com/janestreet/base/commit/dde0e6ecc22e8de29c3e2d030941b1c5edf476c6
+Patch0:         %{name}-gc.patch
 
 BuildRequires:  ocaml >= 4.04.2
 BuildRequires:  ocaml-dune-devel >= 1.5.1
@@ -43,7 +46,7 @@ The %{name}-devel package contains libraries and signature files for
 developing applications that use %{name}.
 
 %prep
-%autosetup -n %{srcname}-%{version}
+%autosetup -n %{srcname}-%{version} -p1
 
 %build
 dune build %{?_smp_mflags}
@@ -119,6 +122,9 @@ find %{buildroot}%{_libdir}/ocaml -name \*.cmxs -exec chmod a+x {} \+
 %{_libdir}/ocaml/%{srcname}/*/*.mli
 
 %changelog
+* Wed Jan 22 2020 Jerry James <loganjerry@gmail.com> - 0.13.0-3
+- Add -gc patch to fix FTBFS with OCaml 4.10
+
 * Sun Jan 19 2020 Richard W.M. Jones <rjones@redhat.com> - 0.13.0-3
 - OCaml 4.10.0+beta1 rebuild.