pip reproducible.patch fails to apply

[Pacman99]

Description

Any pypi2nix command fails due to an error in building pip. The pip reproducible patch from nixpkgs fails to apply because of a missing file. Pip and wheels builds fine from nixpkgs.
<detailed description of error # Traceback

% pypi2nix --version
% pypi2nix -r requirements.txt

INFO: pypi2nix v2.0.4 running ...
INFO: Downloading wheels and creating wheelhouse ...
INFO: Downloading runtime requirements
these derivations will be built:
  /nix/store/flysrk7vgd4qrzvc25wyshwyg3ws321s-python3.8-pip-20.1.1.drv
  /nix/store/i335sc5qsgk1vwf837qjdsmmrq80z0pk-python3.8-wheel-0.33.6.drv
  /nix/store/d1vw8f088xl856l1h5b0v0xazb60xnki-python3-3.8.3-env.drv
building '/nix/store/flysrk7vgd4qrzvc25wyshwyg3ws321s-python3.8-pip-20.1.1.drv'...
building '/nix/store/i335sc5qsgk1vwf837qjdsmmrq80z0pk-python3.8-wheel-0.33.6.drv'...
Sourcing python-recompile-bytecode-hook.sh
Sourcing python-remove-tests-dir-hook
Sourcing python-catch-conflicts-hook.sh
Sourcing python-remove-bin-bytecode-hook.sh
Sourcing python-imports-check-hook.sh
Using pythonImportsCheckPhase
Sourcing python-namespaces-hook
Sourcing pip-install-hook
Using pipInstallPhase
Sourcing setuptools-build-hook
Using setuptoolsBuildPhase
Using setuptoolsShellHook
Sourcing python-recompile-bytecode-hook.sh
Sourcing python-remove-tests-dir-hook
Sourcing python-remove-bin-bytecode-hook.sh
Sourcing python-imports-check-hook.sh
Using pythonImportsCheckPhase
Sourcing python-namespaces-hook
Sourcing pip-install-hook
Using pipInstallPhase
Sourcing setuptools-build-hook
Using setuptoolsBuildPhase
Using setuptoolsShellHook
Using setuptoolsShellHook
unpacking sources
unpacking source archive /nix/store/pham2w174fjmc99f6sg3w98wac2r484f-pip-b8c16a0
unpacking sources
unpacking source archive /nix/store/ps72n0awkcgf1jp2cpr7awrf5xvd007w-wheel-0.33.6.tar.gz
source root is wheel-0.33.6
setting SOURCE_DATE_EPOCH to timestamp 1566122927 of file wheel-0.33.6/setup.cfg
patching sources
configuring
no configure script, doing nothing
building
Executing setuptoolsBuildPhase
source root is pip-b8c16a0
setting SOURCE_DATE_EPOCH to timestamp 315619200 of file pip-b8c16a0/tox.ini
patching sources
applying patch /nix/store/iz5gi7nz4xdxfcb8372dmi4rkclpqd4m-reproducible.patch
can't find file to patch at input line 5
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff --git a/src/pip/_internal/operations/install/wheel.py b/src/pip/_internal/operations/install/wheel.py
|index e7315ee4..4e36b03d 100644
|--- a/src/pip/_internal/operations/install/wheel.py
|+++ b/src/pip/_internal/operations/install/wheel.py
--------------------------
File to patch:
Skip this patch? [y]
Skipping patch.
1 out of 1 hunk ignored
builder for '/nix/store/flysrk7vgd4qrzvc25wyshwyg3ws321s-python3.8-pip-20.1.1.drv' failed with exit code 1
cannot build derivation '/nix/store/d1vw8f088xl856l1h5b0v0xazb60xnki-python3-3.8.3-env.drv': 1 dependencies couldn't be built
error: build of '/nix/store/d1vw8f088xl856l1h5b0v0xazb60xnki-python3-3.8.3-env.drv' failed