diff --git a/contrib/packaging/hgpackaging/pyoxidizer.py b/contrib/packaging/hgpackaging/pyoxidizer.py
new file mode 100644
--- /dev/null
+++ b/contrib/packaging/hgpackaging/pyoxidizer.py
@@ -0,0 +1,70 @@
+# pyoxidizer.py - Functionality for packaging using PyOxidizer.
+#
+# Copyright 2019 Gregory Szorc <gregory.szorc@gmail.com>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+import os
+import pathlib
+import shutil
+import subprocess
+
+
+def build_pyoxidizer(
+    source_dir: pathlib.Path,
+    build_dir: pathlib.Path,
+    pyoxidizer_bin: pathlib.Path = 'pyoxidizer',
+):
+    """Build Mercurial using PyOxidizer.
+
+    The resulting files will be copied to ``build_dir``.
+    """
+
+    config_path = source_dir / 'rust' / 'hgcli'
+    staging_dir = build_dir / 'staging'
+
+    if staging_dir.exists():
+        shutil.rmtree(staging_dir)
+
+    res = subprocess.run(
+        [str(pyoxidizer_bin), 'app-path', '--release', str(config_path)],
+        check=True,
+        capture_output=True,
+    )
+
+    app_path = pathlib.Path(res.stdout.strip())
+
+    subprocess.run(
+        [str(pyoxidizer_bin), 'build', '--release', str(config_path)],
+        check=True,
+    )
+
+    # PyOxidizer's application staging doesn't currently handle resource
+    # files properly. So we need to massage the file layout so things work.
+    staging_dir.mkdir(parents=True)
+
+    # All files in the root directory are fine.
+    for p in os.listdir(app_path):
+        p = app_path / p
+
+        if p.is_file():
+            dest = staging_dir / p.name
+            shutil.copyfile(p, dest)
+
+    # For the lib directory, only copy .py and .pyc files: we'll manage
+    # the resource files ourselves later.
+    for root, dirs, files in os.walk(app_path / 'lib'):
+        dirs.sort()
+
+        rel_dir = (app_path / 'lib').relative_to(app_path)
+
+        for f in sorted(files):
+            if not f.endswith(('.py', '.pyc')):
+                continue
+
+            dest_dir = staging_dir / rel_dir
+            dest_dir.mkdir(parents=True, exist_ok=True)
+
+            dest = dest_dir / f
+            shutil.copyfile(root / f, dest)
diff --git a/rust/hgcli/Cargo.lock b/rust/hgcli/Cargo.lock
new file mode 100644
--- /dev/null
+++ b/rust/hgcli/Cargo.lock
@@ -0,0 +1,336 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.6"
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+
+[[package]]
+name = "autocfg"
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+
+[[package]]
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diff --git a/rust/hgcli/Cargo.toml b/rust/hgcli/Cargo.toml
new file mode 100644
--- /dev/null
+++ b/rust/hgcli/Cargo.toml
@@ -0,0 +1,14 @@
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+
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+default = []
+jemalloc = ["jemallocator-global", "pyembed/jemalloc"]
diff --git a/rust/hgcli/pyoxidizer.bzl b/rust/hgcli/pyoxidizer.bzl
new file mode 100644
--- /dev/null
+++ b/rust/hgcli/pyoxidizer.bzl
@@ -0,0 +1,37 @@
+# This file controls the PyOxidizer build configuration. See the
+# pyoxidizer crate's documentation for extensive documentation
+# on this file format.
+
+BUILD_PATH = CWD + "/../../build/pyoxidizer"
+
+Config(
+    application_name="hg",
+    python_distribution=default_python_distribution(),
+    embedded_python_config=EmbeddedPythonConfig(
+        legacy_windows_fs_encoding=True,
+        legacy_windows_stdio=True,
+        sys_paths=["$ORIGIN/lib"],
+    ),
+    python_run_mode=python_run_mode_eval("import hgdemandimport; hgdemandimport.enable(); import mercurial.dispatch; mercurial.dispatch.run()"),
+    packaging_rules=[
+        # Mercurial requires a fully featured Python because extensions may use
+        # anything.
+        StdlibExtensionsPolicy("all"),
+        Stdlib(include_source=True),
+        SetupPyInstall(
+            package_path="../..",
+            extra_global_arguments=["clean", "--all", "build"],
+            # Our code doesn't yet work with the in-memory importer. So package
+            # relative to the executable for now.
+            install_location="app-relative:lib",
+        ),
+    ]
+)
+
+# END OF COMMON USER-ADJUSTED SETTINGS.
+#
+# Everything below this is typically managed by PyOxidizer and doesn't need
+# to be updated by people.
+
+PYOXIDIZER_VERSION = "0.5.0"
+PYOXIDIZER_COMMIT = "9132d0d6e089d0f31526b3134d8be078ca586c31"
diff --git a/rust/hgcli/src/main.rs b/rust/hgcli/src/main.rs
new file mode 100644
--- /dev/null
+++ b/rust/hgcli/src/main.rs
@@ -0,0 +1,30 @@
+use pyembed::{default_python_config, MainPythonInterpreter};
+
+fn main() {
+    // The following code is in a block so the MainPythonInterpreter is destroyed in an
+    // orderly manner, before process exit.
+    let code = {
+        // Load the default Python configuration as derived by the PyOxidizer config
+        // file used at build time.
+        let config = default_python_config();
+
+        // Construct a new Python interpreter using that config, handling any errors
+        // from construction.
+        match MainPythonInterpreter::new(config) {
+            Ok(mut interp) => {
+                // And run it using the default run configuration as specified by the
+                // configuration. If an uncaught Python exception is raised, handle it.
+                // This includes the special SystemExit, which is a request to terminate the
+                // process.
+                interp.run_as_main()
+            }
+            Err(msg) => {
+                eprintln!("{}", msg);
+                1
+            }
+        }
+    };
+
+    // And exit the process according to code execution results.
+    std::process::exit(code);
+}
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -568,7 +568,11 @@
 
 class hgbuildscripts(build_scripts):
     def run(self):
-        if os.name != 'nt' or self.distribution.pure:
+        if (
+            os.name != 'nt'
+            or self.distribution.pure
+            or 'PYOXIDIZER' in os.environ
+        ):
             return build_scripts.run(self)
 
         exebuilt = False