pyoxidizer: add the user site to `sys.path` on macOS

This allows 3rd party extensions that are installed with `pip` to be picked up,
similar to what we do on Windows.  PyOxidizer has a bug that prevents this from
working without this extra help (see 95af358fcdfe), though it appears there's
another wrinkle here with `sys._framework` too.

I needed this to see if the problem[1] loading the keyring extension on Windows
also occurs on macOS (it doesn't).

[1] https://github.com/indygreg/PyOxidizer/issues/445

Differential Revision: https://phab.mercurial-scm.org/D11452

rust/hgcli/pyoxidizer.bzl

@@ -1,321 +1,335 b''
 # The following variables can be passed in as parameters:
 #
 # VERSION
 #   Version string of program being produced.
 #
 # MSI_NAME
 #   Root name of MSI installer.
 #
 # EXTRA_MSI_FEATURES
 #   ; delimited string of extra features to advertise in the built MSA.
 #
 # SIGNING_PFX_PATH
 #   Path to code signing certificate to use.
 #
 # SIGNING_PFX_PASSWORD
 #   Password to code signing PFX file defined by SIGNING_PFX_PATH.
 #
 # SIGNING_SUBJECT_NAME
 #   String fragment in code signing certificate subject name used to find
 #   code signing certificate in Windows certificate store.
 #
 # TIME_STAMP_SERVER_URL
 #   URL of time-stamp token authority (RFC 3161) servers to stamp code signatures.
 
 ROOT = CWD + "/../.."
 
 VERSION = VARS.get("VERSION", "5.8")
 MSI_NAME = VARS.get("MSI_NAME", "mercurial")
 EXTRA_MSI_FEATURES = VARS.get("EXTRA_MSI_FEATURES")
 SIGNING_PFX_PATH = VARS.get("SIGNING_PFX_PATH")
 SIGNING_PFX_PASSWORD = VARS.get("SIGNING_PFX_PASSWORD", "")
 SIGNING_SUBJECT_NAME = VARS.get("SIGNING_SUBJECT_NAME")
 TIME_STAMP_SERVER_URL = VARS.get("TIME_STAMP_SERVER_URL", "http://timestamp.digicert.com")
 
 IS_WINDOWS = "windows" in BUILD_TARGET_TRIPLE
 IS_MACOS = "darwin" in BUILD_TARGET_TRIPLE
 
 # Code to run in Python interpreter.
 RUN_CODE = """
 import os
 import sys
 extra_path = os.environ.get('PYTHONPATH')
 if extra_path is not None:
     # extensions and hooks expect a working python environment
     # We do not prepend the values because the Mercurial library wants to be in
     # the front of the sys.path to avoid picking up other installations.
     sys.path.extend(extra_path.split(os.pathsep))
 # Add user site to sys.path to load extensions without the full path
 if os.name == 'nt':
     vi = sys.version_info
     appdata = os.environ.get('APPDATA')
     if appdata:
         sys.path.append(
             os.path.join(
                 appdata,
                 'Python',
                 'Python%d%d' % (vi[0], vi[1]),
                 'site-packages',
             )
         )
+elif sys.platform == "darwin":
+    vi = sys.version_info
+
+    def joinuser(*args):
+        return os.path.expanduser(os.path.join(*args))
+
+    # Note: site.py uses `sys._framework` instead of hardcoding "Python" as the
+    #   3rd arg, but that is set to an empty string in an oxidized binary.  It
+    #   has a fallback to ~/.local when `sys._framework` isn't set, but we want
+    #   to match what the system python uses, so it sees pip installed stuff.
+    usersite = joinuser("~", "Library", "Python",
+                        "%d.%d" % vi[:2], "lib/python/site-packages")
+
+    sys.path.append(usersite)
 import hgdemandimport;
 hgdemandimport.enable();
 from mercurial import dispatch;
 dispatch.run();
 """
 
 set_build_path(ROOT + "/build/pyoxidizer")
 
 def make_distribution():
     return default_python_distribution(python_version = "3.9")
 
 def resource_callback(policy, resource):
     if not (IS_WINDOWS or IS_MACOS):
         resource.add_location = "in-memory"
         return
 
     # We use a custom resource routing policy to influence where things are loaded
     # from.
     #
     # For Python modules and resources, we load from memory if they are in
     # the standard library and from the filesystem if not. This is because
     # parts of Mercurial and some 3rd party packages aren't yet compatible
     # with memory loading.
     #
     # For Python extension modules, we load from the filesystem because
     # this yields greatest compatibility.
     if type(resource) in ("PythonModuleSource", "PythonPackageResource", "PythonPackageDistributionResource"):
         if resource.is_stdlib:
             resource.add_location = "in-memory"
         else:
             resource.add_location = "filesystem-relative:lib"
 
     elif type(resource) == "PythonExtensionModule":
         resource.add_location = "filesystem-relative:lib"
 
 def make_exe(dist):
     """Builds a Rust-wrapped Mercurial binary."""
     packaging_policy = dist.make_python_packaging_policy()
 
     # Extension may depend on any Python functionality. Include all
     # extensions.
     packaging_policy.extension_module_filter = "all"
     packaging_policy.resources_location = "in-memory"
     if IS_WINDOWS or IS_MACOS:
         packaging_policy.resources_location_fallback = "filesystem-relative:lib"
     packaging_policy.register_resource_callback(resource_callback)
 
     config = dist.make_python_interpreter_config()
     config.allocator_backend = "default"
     config.run_command = RUN_CODE
 
     # We want to let the user load extensions from the file system
     config.filesystem_importer = True
 
     # We need this to make resourceutil happy, since it looks for sys.frozen.
     config.sys_frozen = True
     config.legacy_windows_stdio = True
 
     exe = dist.to_python_executable(
         name = "hg",
         packaging_policy = packaging_policy,
         config = config,
     )
 
     # Add Mercurial to resources.
     exe.add_python_resources(exe.pip_install(["--verbose", ROOT]))
 
     # On Windows, we install extra packages for convenience.
     if IS_WINDOWS:
         exe.add_python_resources(
             exe.pip_install(["-r", ROOT + "/contrib/packaging/requirements-windows-py3.txt"]),
         )
     extra_packages = VARS.get("extra_py_packages", "")
     if extra_packages:
         for extra in extra_packages.split(","):
             extra_src, pkgs = extra.split("=")
             pkgs = pkgs.split(":")
             exe.add_python_resources(exe.read_package_root(extra_src, pkgs))
 
     return exe
 
 def make_manifest(dist, exe):
     m = FileManifest()
     m.add_python_resource(".", exe)
 
     return m
 
 
 # This adjusts the InstallManifest produced from exe generation to provide
 # additional files found in a Windows install layout.
 def make_windows_install_layout(manifest):
     # Copy various files to new install locations. This can go away once
     # we're using the importlib resource reader.
     RECURSIVE_COPIES = {
         "lib/mercurial/locale/": "locale/",
         "lib/mercurial/templates/": "templates/",
     }
     for (search, replace) in RECURSIVE_COPIES.items():
         for path in manifest.paths():
             if path.startswith(search):
                 new_path = path.replace(search, replace)
                 print("copy %s to %s" % (path, new_path))
                 file = manifest.get_file(path)
                 manifest.add_file(file, path = new_path)
 
     # Similar to above, but with filename pattern matching.
     # lib/mercurial/helptext/**/*.txt -> helptext/
     # lib/mercurial/defaultrc/*.rc -> defaultrc/
     for path in manifest.paths():
         if path.startswith("lib/mercurial/helptext/") and path.endswith(".txt"):
             new_path = path[len("lib/mercurial/"):]
         elif path.startswith("lib/mercurial/defaultrc/") and path.endswith(".rc"):
             new_path = path[len("lib/mercurial/"):]
         else:
             continue
 
         print("copying %s to %s" % (path, new_path))
         manifest.add_file(manifest.get_file(path), path = new_path)
 
     extra_install_files = VARS.get("extra_install_files", "")
     if extra_install_files:
         for extra in extra_install_files.split(","):
             print("adding extra files from %s" % extra)
             # TODO: I expected a ** glob to work, but it didn't.
             #
             # TODO: I know this has forward-slash paths. As far as I can tell,
             # backslashes don't ever match glob() expansions in 
             # tugger-starlark, even on Windows.
             manifest.add_manifest(glob(include=[extra + "/*/*"], strip_prefix=extra+"/"))
 
     # We also install a handful of additional files.
     EXTRA_CONTRIB_FILES = [
         "bash_completion",
         "hgweb.fcgi",
         "hgweb.wsgi",
         "logo-droplets.svg",
         "mercurial.el",
         "mq.el",
         "tcsh_completion",
         "tcsh_completion_build.sh",
         "xml.rnc",
         "zsh_completion",
     ]
 
     for f in EXTRA_CONTRIB_FILES:
         manifest.add_file(FileContent(path = ROOT + "/contrib/" + f), directory = "contrib")
 
     # Individual files with full source to destination path mapping.
     EXTRA_FILES = {
         "contrib/hgk": "contrib/hgk.tcl",
         "contrib/win32/postinstall.txt": "ReleaseNotes.txt",
         "contrib/win32/ReadMe.html": "ReadMe.html",
         "doc/style.css": "doc/style.css",
         "COPYING": "Copying.txt",
     }
 
     for source, dest in EXTRA_FILES.items():
         print("adding extra file %s" % dest)
         manifest.add_file(FileContent(path = ROOT + "/" + source), path = dest)
 
     # And finally some wildcard matches.
     manifest.add_manifest(glob(
         include = [ROOT + "/contrib/vim/*"],
         strip_prefix = ROOT + "/"
     ))
     manifest.add_manifest(glob(
         include = [ROOT + "/doc/*.html"],
         strip_prefix = ROOT + "/"
     ))
 
     # But we don't ship hg-ssh on Windows, so exclude its documentation.
     manifest.remove("doc/hg-ssh.8.html")
 
     return manifest
 
 
 def make_msi(manifest):
     manifest = make_windows_install_layout(manifest)
 
     if "x86_64" in BUILD_TARGET_TRIPLE:
         platform = "x64"
     else:
         platform = "x86"
 
     manifest.add_file(
         FileContent(path = ROOT + "/contrib/packaging/wix/COPYING.rtf"),
         path = "COPYING.rtf",
     )
     manifest.remove("Copying.txt")
     manifest.add_file(
         FileContent(path = ROOT + "/contrib/win32/mercurial.ini"),
         path = "defaultrc/mercurial.rc",
     )
     manifest.add_file(
         FileContent(filename = "editor.rc", content = "[ui]\neditor = notepad\n"),
         path = "defaultrc/editor.rc",
     )
 
     wix = WiXInstaller(
         "hg",
         "%s-%s-%s.msi" % (MSI_NAME, VERSION, platform),
         arch = platform,
     )
 
     # Materialize files in the manifest to the install layout.
     wix.add_install_files(manifest)
 
     # From mercurial.wxs.
     wix.install_files_root_directory_id = "INSTALLDIR"
 
     # Pull in our custom .wxs files.
     defines = {
         "PyOxidizer": "1",
         "Platform": platform,
         "Version": VERSION,
         "Comments": "Installs Mercurial version %s" % VERSION,
         "PythonVersion": "3",
         "MercurialHasLib": "1",
     }
 
     if EXTRA_MSI_FEATURES:
         defines["MercurialExtraFeatures"] = EXTRA_MSI_FEATURES
 
     wix.add_wxs_file(
         ROOT + "/contrib/packaging/wix/mercurial.wxs",
         preprocessor_parameters=defines,
     )
 
     # Our .wxs references to other files. Pull those into the build environment.
     for f in ("defines.wxi", "guids.wxi", "COPYING.rtf"):
         wix.add_build_file(f, ROOT + "/contrib/packaging/wix/" + f)
 
     wix.add_build_file("mercurial.ico", ROOT + "/contrib/win32/mercurial.ico")
 
     return wix
 
 
 def register_code_signers():
     if not IS_WINDOWS:
         return
 
     if SIGNING_PFX_PATH:
         signer = code_signer_from_pfx_file(SIGNING_PFX_PATH, SIGNING_PFX_PASSWORD)
     elif SIGNING_SUBJECT_NAME:
         signer = code_signer_from_windows_store_subject(SIGNING_SUBJECT_NAME)
     else:
         signer = None
 
     if signer:
         signer.set_time_stamp_server(TIME_STAMP_SERVER_URL)
         signer.activate()
 
 
 register_code_signers()
 
 register_target("distribution", make_distribution)
 register_target("exe", make_exe, depends = ["distribution"])
 register_target("app", make_manifest, depends = ["distribution", "exe"], default = True)
 register_target("msi", make_msi, depends = ["app"])
 
 resolve_targets()