diff --git a/opam-2.0.7-fix-extlib-source.patch b/opam-2.0.7-fix-extlib-source.patch
new file mode 100644
index 0000000..b03f207
--- /dev/null
+++ b/opam-2.0.7-fix-extlib-source.patch
@@ -0,0 +1,11 @@
+--- opam-2.0.7/src_ext/Makefile.sources.orig	2021-01-23 14:35:11.745266462 +0000
++++ opam-2.0.7/src_ext/Makefile.sources	2021-01-23 14:35:39.052802484 +0000
+@@ -3,7 +3,7 @@
+ 
+ $(call PKG_SAME,cppo)
+ 
+-URL_extlib = http://ygrek.org.ua/p/release/ocaml-extlib/extlib-1.7.5.tar.gz
++URL_extlib = https://github.com/ygrek/ocaml-extlib/releases/download/1.7.5/extlib-1.7.5.tar.gz
+ MD5_extlib = d989951536077563bf4c5e3479c3866f
+ 
+ $(call PKG_SAME,extlib)
diff --git a/opam-Makefile.sources b/opam-Makefile.sources
new file mode 100644
index 0000000..e1af9dd
--- /dev/null
+++ b/opam-Makefile.sources
@@ -0,0 +1,73 @@
+URL_cppo = https://github.com/ocaml-community/cppo/releases/download/v1.6.6/cppo-v1.6.6.tbz
+MD5_cppo = b13afeea6631d7c9b61f95bfd984a542
+
+$(call PKG_SAME,cppo)
+
+URL_extlib = https://ygrek.org/p/release/ocaml-extlib/extlib-1.7.7.tar.gz
+MD5_extlib = 2c620993aecd4b31b3a362b21b55dd94
+
+$(call PKG_SAME,extlib)
+
+URL_re = https://github.com/ocaml/ocaml-re/releases/download/1.9.0/re-1.9.0.tbz
+MD5_re = bddaed4f386a22cace7850c9c7dac296
+
+$(call PKG_SAME,re)
+
+URL_cmdliner = http://erratique.ch/software/cmdliner/releases/cmdliner-1.0.4.tbz
+MD5_cmdliner = fe2213d0bc63b1e10a2d0aa66d2fc8d9
+
+$(call PKG_SAME,cmdliner)
+
+URL_ocamlgraph = http://ocamlgraph.lri.fr/download/ocamlgraph-1.8.8.tar.gz
+MD5_ocamlgraph = 9d71ca69271055bd22d0dfe4e939831a
+
+$(call PKG_SAME,ocamlgraph)
+
+URL_cudf = https://gforge.inria.fr/frs/download.php/36602/cudf-0.9.tar.gz
+MD5_cudf = a4c0e652e56e74c7b388a43f9258d119
+
+$(call PKG_SAME,cudf)
+
+URL_dose3 = https://gforge.inria.fr/frs/download.php/file/36063/dose3-5.0.1.tar.gz
+MD5_dose3 = e7d4b1840383c6732f29a47c08ba5650
+
+$(call PKG_SAME,dose3)
+
+URL_mccs = https://github.com/AltGr/ocaml-mccs/archive/1.1+11.tar.gz
+MD5_mccs = 9c0038d0e945f742b9320a662566288b
+
+$(call PKG_SAME,mccs)
+
+URL_opam-file-format = https://github.com/ocaml/opam-file-format/archive/2.1.1.tar.gz
+MD5_opam-file-format = c1949c5dff062c754d0642c7eded794f
+
+$(call PKG_SAME,opam-file-format)
+
+URL_result = https://github.com/janestreet/result/releases/download/1.5/result-1.5.tbz
+MD5_result = 1b82dec78849680b49ae9a8a365b831b
+
+$(call PKG_SAME,result)
+
+# NB If minimum OCaml version for Dune changes, update DUNE_SECONDARY in configure.ac
+URL_dune-local = https://github.com/ocaml/dune/releases/download/2.6.2/dune-2.6.2.tbz
+MD5_dune-local = 8fe40bef051975e798537d3450b61129
+
+$(call PKG_SAME,dune-local)
+
+URL_PKG_findlib = http://download.camlcity.org/download/findlib-1.8.1.tar.gz
+MD5_PKG_findlib = 18ca650982c15536616dea0e422cbd8c
+
+URL_PKG_ocamlbuild = https://github.com/ocaml/ocamlbuild/archive/0.14.0.tar.gz
+MD5_PKG_ocamlbuild = a7bf2fe594cd16907807c756b14d501f
+
+URL_PKG_topkg = http://erratique.ch/software/topkg/releases/topkg-1.0.2.tbz
+MD5_PKG_topkg = b4925b2c37f73f8f0b79ea07ab15ff67
+
+URL_seq = https://github.com/c-cube/seq/archive/0.2.2.tar.gz
+MD5_seq = 9033e02283aa3bde9f97f24e632902e3
+
+# This is necessary as long as a patch is used to rename seq.ml and seq.mli
+ensure-seq-patched.stamp: seq.stamp
+	rm -f seq/src/seq.ml seq/src/seq.mli
+
+$(call PKG_SAME,seq)
diff --git a/opam.spec b/opam.spec
index cc16a7d..4ffbb37 100644
--- a/opam.spec
+++ b/opam.spec
@@ -1,5 +1,6 @@
+%define gitver %(echo %version | tr _ -)
 Name:          opam
-Version:       2.0.6
+Version:       2.1.0_beta4
 Release:       1mamba
 Summary:       opam is a source-based package manager for OCaml
 Group:         Development/Tools
@@ -7,8 +8,9 @@ Vendor:        openmamba
 Distribution:  openmamba
 Packager:      Silvan Calarco <silvan.calarco@mambasoft.it>
 URL:           https://opam.ocaml.org
-## GITSOURCE https://github.com/ocaml/opam.git 2.0.4
-Source:        https://github.com/ocaml/opam.git/%{version}/opam-%{version}.tar.bz2
+Source:        https://github.com/ocaml/opam.git/%{gitver}/opam-%{version}.tar.bz2
+Source1:       opam-Makefile.sources
+Patch0:        opam-2.0.7-fix-extlib-source.patch
 License:       LGPL
 ## AUTOBUILDREQ-BEGIN
 BuildRequires: glibc-devel
@@ -18,6 +20,8 @@ BuildRequires: libstdc++6-devel
 BuildRequires: ocaml
 BuildRequires: ocaml-re
 BuildRequires: ocaml-compiler-libs
+BuildRequires: ocaml-cppo
+BuildRequires: dune
 BuildRoot:     %{_tmppath}/%{name}-%{version}-root
 
 %description
@@ -27,21 +31,26 @@ opam is a source-based package manager. It supports multiple simultaneous compil
 
 %prep
 %setup -q
-# 2.0.4: fix blocking error in install due just to dune warnings
-sed -i "s|; false ;|; true ;|" doc/Makefile
+#% patch0 -p1
+## 2.0.4: fix blocking error in install due just to dune warnings
+#sed -i "s|; false ;|; true ;|" doc/Makefile
+
+#install %{SOURCE1} src_ext/Makefile.sources
+#rm -rf src_ext/patches/seq
 
 %build
 %configure
    
 make lib-ext all -j1 \
   OCAMLC='ocamlc -unsafe-string' \
-  OCAMLOPT='ocamlopt -unsafe-string'
+  OCAMLOPT='ocamlopt -unsafe-string' \
+  DUNE_ARGS="-j1"
 
 %install
 [ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
 %makeinstall
 
-install -d %{buildroot}%{_docdir}
+#install -d %{buildroot}%{_docdir}
 #mv %{buildroot}/usr/doc/opam-installer %{buildroot}%{_docdir}/opam
 #rmdir %{buildroot}/usr/doc
   
@@ -60,6 +69,12 @@ install -d %{buildroot}%{_docdir}
 %doc AUTHORS LICENSE
 
 %changelog
+* Sat Jan 23 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 2.1.0_beta4-1mamba
+- update to 2.1.0_beta4
+
+* Sat Jan 23 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 2.0.7-1mamba
+- update to 2.0.7
+
 * Sat Feb 08 2020 Automatic Build System <autodist@mambasoft.it> 2.0.6-1mamba
 - automatic version update by autodist