Wrong checksum for core 109.08.00 via `opam install core`

gistfile1.txt

amir$ opam install core
The following actions will be performed:
 - install ocamlfind.1.3.3 [required by core]
 - install ounit.1.1.2 [required by core]
 - install res.3.2.0 [required by core]
 - install type_conv.109.08.00 [required by core]
 - install bin_prot.109.08.00 [required by core]
 - install comparelib.109.08.00 [required by core]
 - install fieldslib.109.08.00 [required by core]
 - install pa_ounit.109.08.00 [required by core]
 - install pipebang.109.08.00 [required by core]
 - install sexplib.109.08.00 [required by core]
 - install variantslib.109.08.00 [required by core]
 - install core.109.08.00
12 to install | 0 to reinstall | 0 to upgrade | 0 to downgrade | 0 to remove
Do you want to continue ? [Y/n] y

=-=-= ocamlfind.1.3.3 =-=-=
Downloading http://opam.ocamlpro.com/archives/ocamlfind.1.3.3+opam.tar.gz.
Extracting /Users/amir/.opam/archives/ocamlfind.1.3.3+opam.tar.gz.
Building ocamlfind.1.3.3:
  ./configure -bindir /Users/amir/.opam/system/bin -sitelib /Users/amir/.opam/system/lib -mandir /Users/amir/.opam/system/man -config /Users/amir/.opam/system/lib/findlib.conf -no-topfind
  make all
  make opt
  make install
  ocamlfind remove dbm
Installing ocamlfind.1.3.3.

=-=-= ounit.1.1.2 =-=-=
Downloading http://opam.ocamlpro.com/archives/ounit.1.1.2+opam.tar.gz.
Extracting /Users/amir/.opam/archives/ounit.1.1.2+opam.tar.gz.
Building ounit.1.1.2:
  make build
  make install
Installing ounit.1.1.2.

=-=-= res.3.2.0 =-=-=
Downloading http://opam.ocamlpro.com/archives/res.3.2.0+opam.tar.gz.
Extracting /Users/amir/.opam/archives/res.3.2.0+opam.tar.gz.
Building res.3.2.0:
  make
  make install
Installing res.3.2.0.

=-=-= type_conv.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/type_conv.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/type_conv.109.08.00+opam.tar.gz.
Building type_conv.109.08.00:
  make
  make install
Installing type_conv.109.08.00.

=-=-= bin_prot.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/bin_prot.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/bin_prot.109.08.00+opam.tar.gz.
Building bin_prot.109.08.00:
  make
  make install
Installing bin_prot.109.08.00.

=-=-= comparelib.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/comparelib.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/comparelib.109.08.00+opam.tar.gz.
Building comparelib.109.08.00:
  make
  make install
Installing comparelib.109.08.00.

=-=-= fieldslib.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/fieldslib.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/fieldslib.109.08.00+opam.tar.gz.
Building fieldslib.109.08.00:
  make
  make install
Installing fieldslib.109.08.00.

=-=-= pa_ounit.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/pa_ounit.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/pa_ounit.109.08.00+opam.tar.gz.
Building pa_ounit.109.08.00:
  make
  make install
Installing pa_ounit.109.08.00.

=-=-= pipebang.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/pipebang.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/pipebang.109.08.00+opam.tar.gz.
Building pipebang.109.08.00:
  make
  make install
Installing pipebang.109.08.00.

=-=-= sexplib.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/sexplib.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/sexplib.109.08.00+opam.tar.gz.
Building sexplib.109.08.00:
  make
  make install
Installing sexplib.109.08.00.

=-=-= variantslib.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/variantslib.109.08.00+opam.tar.gz.
Extracting /Users/amir/.opam/archives/variantslib.109.08.00+opam.tar.gz.
Building variantslib.109.08.00:
  make
  make install
Installing variantslib.109.08.00.

=-=-= core.109.08.00 =-=-=
Downloading http://opam.ocamlpro.com/archives/core.109.08.00+opam.tar.gz.
The compilation of core.109.08.00 failed.
Uninstalling core.109.08.00:
  ocamlfind remove core


==== ERROR [while installing core.109.08.00] ====
Internal error:
  Wrong checksum for http://opam.ocamlpro.com/archives/core.109.08.00+opam.tar.gz
'opam install core' failed.
dhcp-128-232-142-178:~ amir$ which ocamlfind
/Users/amir/.opam/system/bin/ocamlfind
amir$