Issues with re-adding python support for ledger

[dcao]

I'm currently trying to build a modified formula for the ledger command-line accounting program on my MacBook Pro M1; in particular, the latest version adds support for Python 3, so I figured I'd be able to re-add the Python support which was removed a few commits back. My modified ledger.rb formula is below (pretty much the only modification is adding --python and -DUSE_PYTHON=1 to the args):

 class Ledger < Formula
  desc "Command-line, double-entry accounting tool"
  homepage "https://ledger-cli.org/"
  url "https://github.com/ledger/ledger/archive/v3.2.1.tar.gz"
  sha256 "92bf09bc385b171987f456fe3ee9fa998ed5e40b97b3acdd562b663aa364384a"
  revision 5
  head "https://github.com/ledger/ledger.git"

  depends_on "cmake" => :build
  depends_on "boost"
  depends_on "boost-python3"
  depends_on "gmp"
  depends_on "mpfr"
  depends_on "[email protected]"

  def install
    ENV.cxx11
    ENV.prepend_path "PATH", Formula["[email protected]"].opt_libexec/"bin"

    args = %W[
      --jobs=#{ENV.make_jobs}
      --output=build
      --prefix=#{prefix}
      --boost=#{Formula["boost"].opt_prefix}
      --python
      --
      -DBUILD_DOCS=1
      -DBUILD_WEB_DOCS=1
      -DBoost_NO_BOOST_CMAKE=ON
      -DUSE_PYTHON=1
      -DPython_FIND_VERSION_MAJOR=3
    ] + std_cmake_args
    system "./acprep", "opt", "make", *args
    system "./acprep", "opt", "make", "doc", *args
    system "./acprep", "opt", "make", "install", *args

    (pkgshare/"examples").install Dir["test/input/*.dat"]
    pkgshare.install "contrib"
    pkgshare.install "python/demo.py"
    elisp.install Dir["lisp/*.el", "lisp/*.elc"]
    bash_completion.install pkgshare/"contrib/ledger-completion.bash"
  end

  test do
    balance = testpath/"output"
    system bin/"ledger",
      "--args-only",
      "--file", "#{pkgshare}/examples/sample.dat",
      "--output", balance,
      "balance", "--collapse", "equity"
    assert_equal "          $-2,500.00  Equity", balance.read.chomp
    assert_equal 0, $CHILD_STATUS.exitstatus

    system "python", pkgshare/"demo.py"
  end
end

However, when I try to install this formula, I get an error having to do with copying the ledger python library into the site-packages directory under where the Python framework is installed:

... snip ...
==> ./acprep opt make install --jobs=8 --output=build --prefix=/opt/homebrew/Cel
Last 15 lines from /Users/david/Library/Logs/Homebrew/ledger/03.acprep:
-- Installing: /opt/homebrew/Cellar/ledger/3.2.1_5/include/ledger/views.h
-- Installing: /opt/homebrew/Cellar/ledger/3.2.1_5/include/ledger/xact.h
-- Installing: /opt/homebrew/Cellar/ledger/3.2.1_5/include/ledger/system.hh
-- Installing: /opt/homebrew/Cellar/[email protected]/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/ledger.so
CMake Error at src/cmake_install.cmake:144 (file):
  file INSTALL cannot copy file
  "/tmp/ledger-20210213-73787-qaj5eu/ledger-3.2.1/build/ledger.so" to
  "/opt/homebrew/Cellar/[email protected]/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/ledger.so":
  Operation not permitted.
Call Stack (most recent call first):
  cmake_install.cmake:42 (include)
... snip ...

I was wondering if I could get some help resolving this issue with my formula?