Install pygit2 in a Python VirtualEnv

pygit2.sh

#!/bin/sh
set -e

if [ "${VIRTUAL_ENV}" = "" ]; then
    echo "Error: Not in a virtual env"
    exit 1
fi

OS=$(uname -s)

set -u

SRC="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )/_tmp"
TARGET=${VIRTUAL_ENV}

test -d ${SRC} || mkdir ${SRC}

cd ${SRC}

test -d libgit2 || git clone git://github.com/libgit2/libgit2.git
test -d pygit2 || git clone git://github.com/libgit2/pygit2.git

# Building libgit2
cd ${SRC}/libgit2
git checkout v0.19.0
rm -rf build && mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=${TARGET}
cmake --build . --target install

# Building pygit2
cd ${SRC}/pygit2
git checkout v0.19.0
LIBGIT2=${TARGET} python setup.py build_ext -R ${TARGET}/lib
python setup.py build

if [ "${OS}" = "Darwin" ]; then
    install_name_tool -add_rpath ${TARGET}/lib $(find build -name '_pygit2.so')
    install_name_tool -change libgit2.0.dylib @rpath/libgit2.0.dylib $(find build -name '_pygit2.so')
fi

python setup.py install

rm -rf ${SRC}

I am trying to use this script to install pygit2 and libgit2 v0.22.0 on OSX for which I changed the version on line 25 and 33 and libgit2.0.dylib on line 39 to libgit2.22.dylib. Got the following error:

HEAD is now at 1263084... Get ready to release v0.22.0
running build_ext
Traceback (most recent call last):
  File "setup.py", line 197, in <module>
    cmdclass=cmdclass)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 971, in run_command
    cmd_obj.ensure_finalized()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 109, in ensure_finalized
    self.finalize_options()
  File "/Users/naiquevin/.virtualenvs/autorel/lib/python2.7/site-packages/setuptools/command/build_ext.py", line 105, in finalize_options
    _build_ext.finalize_options(self)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/build_ext.py", line 140, in finalize_options
    ('plat_name', 'plat_name'),
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 298, in set_undefined_options
    src_cmd_obj.ensure_finalized()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 109, in ensure_finalized
    self.finalize_options()
  File "setup.py", line 103, in finalize_options
    ffi, C = get_ffi()
  File "pygit2/_utils.py", line 101, in get_ffi
    include_dirs=[libgit2_include], library_dirs=[libgit2_lib])
  File "/Users/naiquevin/helpshift/code/autorelease/_tmp/pygit2/.eggs/cffi-0.9.2-py2.7-macosx-10.9-intel.egg/cffi/api.py", line 367, in verify
    lib = self.verifier.load_library()
  File "/Users/naiquevin/helpshift/code/autorelease/_tmp/pygit2/.eggs/cffi-0.9.2-py2.7-macosx-10.9-intel.egg/cffi/verifier.py", line 97, in load_library
    return self._load_library()
  File "/Users/naiquevin/helpshift/code/autorelease/_tmp/pygit2/.eggs/cffi-0.9.2-py2.7-macosx-10.9-intel.egg/cffi/verifier.py", line 207, in _load_library
    return self._vengine.load_library()
  File "/Users/naiquevin/helpshift/code/autorelease/_tmp/pygit2/.eggs/cffi-0.9.2-py2.7-macosx-10.9-intel.egg/cffi/vengine_cpy.py", line 153, in load_library
    raise ffiplatform.VerificationError(error)
cffi.ffiplatform.VerificationError: importing '/Users/naiquevin/helpshift/code/autorelease/_tmp/pygit2/pygit2/__pycache__/pygit2_cffi_93ecb84x5470904.so': dlopen(/Users/naiquevin/helpshift/code/autoreleas
e/_tmp/pygit2/pygit2/__pycache__/pygit2_cffi_93ecb84x5470904.so, 2): Library not loaded: libgit2.22.dylib
  Referenced from: /Users/naiquevin/helpshift/code/autorelease/_tmp/pygit2/pygit2/__pycache__/pygit2_cffi_93ecb84x5470904.so
  Reason: image not found

Any idea about this?