--- a/contrib/packaging/hgpackaging/cli.py	Mon Apr 20 18:24:35 2020 -0700
+++ b/contrib/packaging/hgpackaging/cli.py	Mon Apr 20 17:42:50 2020 -0700
@@ -50,6 +50,7 @@
 
 def build_wix(
     name=None,
+    pyoxidizer_target=None,
     python=None,
     version=None,
     sign_sn=None,
@@ -60,16 +61,29 @@
     extra_wxs=None,
     extra_features=None,
 ):
+    if not pyoxidizer_target and not python:
+        raise Exception("--python required unless building with PyOxidizer")
+
+    if python and not os.path.isabs(python):
+        raise Exception("--python arg must be an absolute path")
+
     kwargs = {
         "source_dir": SOURCE_DIR,
-        "python_exe": pathlib.Path(python),
         "version": version,
     }
 
-    if not os.path.isabs(python):
-        raise Exception("--python arg must be an absolute path")
+    if pyoxidizer_target:
+        fn = wix.build_installer_pyoxidizer
+        kwargs["target_triple"] = pyoxidizer_target
+    else:
+        fn = wix.build_installer_py2exe
+        kwargs["python_exe"] = pathlib.Path(python)
 
     if extra_packages_script:
+        if pyoxidizer_target:
+            raise Exception(
+                "pyoxidizer does not support --extra-packages-script"
+            )
         kwargs["extra_packages_script"] = extra_packages_script
     if extra_wxs:
         kwargs["extra_wxs"] = dict(
@@ -87,7 +101,7 @@
             "timestamp_url": sign_timestamp_url,
         }
 
-    wix.build_installer(**kwargs)
+    fn(**kwargs)
 
 
 def get_parser():
@@ -115,8 +129,11 @@
     )
     sp.add_argument("--name", help="Application name", default="Mercurial")
     sp.add_argument(
-        "--python", help="Path to Python executable to use", required=True
+        "--pyoxidizer-target",
+        choices={"i686-pc-windows-msvc", "x86_64-pc-windows-msvc"},
+        help="Build with PyOxidizer targeting this host triple",
     )
+    sp.add_argument("--python", help="Path to Python executable to use")
     sp.add_argument(
         "--sign-sn",
         help="Subject name (or fragment thereof) of certificate "

--- a/contrib/packaging/hgpackaging/wix.py	Mon Apr 20 18:24:35 2020 -0700
+++ b/contrib/packaging/hgpackaging/wix.py	Mon Apr 20 17:42:50 2020 -0700
@@ -22,6 +22,7 @@
     build_py2exe,
     stage_install,
 )
+from .pyoxidizer import run_pyoxidizer
 from .util import (
     extract_zip_to_directory,
     normalize_windows_version,
@@ -284,7 +285,7 @@
     return doc.toprettyxml()
 
 
-def build_installer(
+def build_installer_py2exe(
     source_dir: pathlib.Path,
     python_exe: pathlib.Path,
     msi_name='mercurial',
@@ -294,7 +295,7 @@
     extra_features: typing.Optional[typing.List[str]] = None,
     signing_info: typing.Optional[typing.Dict[str, str]] = None,
 ):
-    """Build a WiX MSI installer.
+    """Build a WiX MSI installer using py2exe.
 
     ``source_dir`` is the path to the Mercurial source tree to use.
     ``arch`` is the target architecture. either ``x86`` or ``x64``.
@@ -355,6 +356,50 @@
         staging_dir,
         arch,
         version=version,
+        python2=True,
+        msi_name=msi_name,
+        extra_wxs=extra_wxs,
+        extra_features=extra_features,
+        signing_info=signing_info,
+    )
+
+
+def build_installer_pyoxidizer(
+    source_dir: pathlib.Path,
+    target_triple: str,
+    msi_name='mercurial',
+    version=None,
+    extra_wxs: typing.Optional[typing.Dict[str, str]] = None,
+    extra_features: typing.Optional[typing.List[str]] = None,
+    signing_info: typing.Optional[typing.Dict[str, str]] = None,
+):
+    """Build a WiX MSI installer using PyOxidizer."""
+    hg_build_dir = source_dir / "build"
+    build_dir = hg_build_dir / ("wix-%s" % target_triple)
+    staging_dir = build_dir / "stage"
+
+    arch = "x64" if "x86_64" in target_triple else "x86"
+
+    build_dir.mkdir(parents=True, exist_ok=True)
+    run_pyoxidizer(source_dir, build_dir, staging_dir, target_triple)
+
+    # We also install some extra files.
+    process_install_rules(EXTRA_INSTALL_RULES, source_dir, staging_dir)
+
+    # And remove some files we don't want.
+    for f in STAGING_REMOVE_FILES:
+        p = staging_dir / f
+        if p.exists():
+            print('removing %s' % p)
+            p.unlink()
+
+    return run_wix_packaging(
+        source_dir,
+        build_dir,
+        staging_dir,
+        arch,
+        version,
+        python2=False,
         msi_name=msi_name,
         extra_wxs=extra_wxs,
         extra_features=extra_features,
@@ -368,6 +413,7 @@
     staging_dir: pathlib.Path,
     arch: str,
     version: str,
+    python2: bool,
     msi_name: typing.Optional[str] = "mercurial",
     extra_wxs: typing.Optional[typing.Dict[str, str]] = None,
     extra_features: typing.Optional[typing.List[str]] = None,
@@ -406,7 +452,8 @@
     if not wix_path.exists():
         extract_zip_to_directory(wix_pkg, wix_path)
 
-    ensure_vc90_merge_modules(build_dir)
+    if python2:
+        ensure_vc90_merge_modules(build_dir)
 
     source_build_rel = pathlib.Path(os.path.relpath(source_dir, build_dir))
 
@@ -425,7 +472,16 @@
     source = wix_dir / 'mercurial.wxs'
     defines['Version'] = version
     defines['Comments'] = 'Installs Mercurial version %s' % version
-    defines['VCRedistSrcDir'] = str(build_dir)
+
+    if python2:
+        defines["PythonVersion"] = "2"
+        defines['VCRedistSrcDir'] = str(build_dir)
+    else:
+        defines["PythonVersion"] = "3"
+
+    if (staging_dir / "lib").exists():
+        defines["MercurialHasLib"] = "1"
+
     if extra_features:
         assert all(';' not in f for f in extra_features)
         defines['MercurialExtraFeatures'] = ';'.join(extra_features)

--- a/contrib/packaging/wix/mercurial.wxs	Mon Apr 20 18:24:35 2020 -0700
+++ b/contrib/packaging/wix/mercurial.wxs	Mon Apr 20 17:42:50 2020 -0700
@@ -79,16 +79,21 @@
         </Directory>
       </Directory>
 
-      <?if $(var.Platform) = "x86" ?>
-        <Merge Id='VCRuntime' DiskId='1' Language='1033'
-              SourceFile='$(var.VCRedistSrcDir)\microsoft.vcxx.crt.x86_msm.msm' />
-        <Merge Id='VCRuntimePolicy' DiskId='1' Language='1033'
-              SourceFile='$(var.VCRedistSrcDir)\policy.x.xx.microsoft.vcxx.crt.x86_msm.msm' />
-      <?else?>
-        <Merge Id='VCRuntime' DiskId='1' Language='1033'
-              SourceFile='$(var.VCRedistSrcDir)\microsoft.vcxx.crt.x64_msm.msm' />
-        <Merge Id='VCRuntimePolicy' DiskId='1' Language='1033'
-              SourceFile='$(var.VCRedistSrcDir)\policy.x.xx.microsoft.vcxx.crt.x64_msm.msm' />
+      <!-- Install VCRedist merge modules on Python 2. On Python 3,
+           vcruntimeXXX.dll is part of the install layout and gets picked up
+           as a regular file. -->
+      <?if $(var.PythonVersion) = "2" ?>
+        <?if $(var.Platform) = "x86" ?>
+          <Merge Id='VCRuntime' DiskId='1' Language='1033'
+                SourceFile='$(var.VCRedistSrcDir)\microsoft.vcxx.crt.x86_msm.msm' />
+          <Merge Id='VCRuntimePolicy' DiskId='1' Language='1033'
+                SourceFile='$(var.VCRedistSrcDir)\policy.x.xx.microsoft.vcxx.crt.x86_msm.msm' />
+        <?else?>
+          <Merge Id='VCRuntime' DiskId='1' Language='1033'
+                SourceFile='$(var.VCRedistSrcDir)\microsoft.vcxx.crt.x64_msm.msm' />
+          <Merge Id='VCRuntimePolicy' DiskId='1' Language='1033'
+                SourceFile='$(var.VCRedistSrcDir)\policy.x.xx.microsoft.vcxx.crt.x64_msm.msm' />
+        <?endif?>
       <?endif?>
     </Directory>
 
@@ -101,10 +106,14 @@
         <ComponentGroupRef Id="hg.group.ROOT" />
         <ComponentGroupRef Id="hg.group.defaultrc" />
         <ComponentGroupRef Id="hg.group.helptext" />
-        <ComponentGroupRef Id="hg.group.lib" />
+        <?ifdef MercurialHasLib?>
+          <ComponentGroupRef Id="hg.group.lib" />
+        <?endif?>
         <ComponentGroupRef Id="hg.group.templates" />
-        <MergeRef Id='VCRuntime' />
-        <MergeRef Id='VCRuntimePolicy' />
+        <?if $(var.PythonVersion) = "2" ?>
+          <MergeRef Id='VCRuntime' />
+          <MergeRef Id='VCRuntimePolicy' />
+        <?endif?>
       </Feature>
       <?ifdef MercurialExtraFeatures?>
         <?foreach EXTRAFEAT in $(var.MercurialExtraFeatures)?>