--- a/contrib/automation/hgautomation/cli.py	Mon Apr 20 17:42:50 2020 -0700
+++ b/contrib/automation/hgautomation/cli.py	Thu Apr 23 17:24:37 2020 -0700
@@ -99,7 +99,12 @@
 
 
 def build_windows_wheel(
-    hga: HGAutomation, aws_region, arch, revision, base_image_name
+    hga: HGAutomation,
+    aws_region,
+    python_version,
+    arch,
+    revision,
+    base_image_name,
 ):
     c = hga.aws_connection(aws_region)
     image = aws.ensure_windows_dev_ami(c, base_image_name=base_image_name)
@@ -110,8 +115,11 @@
 
         windows.synchronize_hg(SOURCE_ROOT, revision, instance)
 
-        for a in arch:
-            windows.build_wheel(instance.winrm_client, a, DIST_PATH)
+        for py_version in python_version:
+            for a in arch:
+                windows.build_wheel(
+                    instance.winrm_client, py_version, a, DIST_PATH
+                )
 
 
 def build_all_windows_packages(
@@ -128,10 +136,18 @@
 
         windows.synchronize_hg(SOURCE_ROOT, revision, instance)
 
+        for py_version in ("2.7", "3.7", "3.8"):
+            for arch in ("x86", "x64"):
+                windows.purge_hg(winrm_client)
+                windows.build_wheel(
+                    winrm_client,
+                    python_version=py_version,
+                    arch=arch,
+                    dest_path=DIST_PATH,
+                )
+
         for arch in ('x86', 'x64'):
             windows.purge_hg(winrm_client)
-            windows.build_wheel(winrm_client, arch, DIST_PATH)
-            windows.purge_hg(winrm_client)
             windows.build_inno_installer(
                 winrm_client, arch, DIST_PATH, version=version
             )
@@ -316,6 +332,13 @@
         'build-windows-wheel', help='Build Windows wheel(s)',
     )
     sp.add_argument(
+        '--python-version',
+        help='Python version to build for',
+        choices={'2.7', '3.7', '3.8'},
+        nargs='*',
+        default=['3.8'],
+    )
+    sp.add_argument(
         '--arch',
         help='Architecture to build for',
         choices={'x86', 'x64'},

--- a/contrib/automation/hgautomation/windows.py	Mon Apr 20 17:42:50 2020 -0700
+++ b/contrib/automation/hgautomation/windows.py	Thu Apr 23 17:24:37 2020 -0700
@@ -79,7 +79,7 @@
 
 BUILD_WHEEL = r'''
 Set-Location C:\hgdev\src
-C:\hgdev\python27-{arch}\Scripts\pip.exe wheel --wheel-dir dist .
+C:\hgdev\python{python_version}-{arch}\python.exe -m pip wheel --wheel-dir dist .
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
@@ -101,8 +101,13 @@
 }}
 '''
 
-X86_WHEEL_FILENAME = 'mercurial-{version}-cp27-cp27m-win32.whl'
-X64_WHEEL_FILENAME = 'mercurial-{version}-cp27-cp27m-win_amd64.whl'
+WHEEL_FILENAME_PYTHON27_X86 = 'mercurial-{version}-cp27-cp27m-win32.whl'
+WHEEL_FILENAME_PYTHON27_X64 = 'mercurial-{version}-cp27-cp27m-win_amd64.whl'
+WHEEL_FILENAME_PYTHON37_X86 = 'mercurial-{version}-cp37-cp37m-win32.whl'
+WHEEL_FILENAME_PYTHON37_X64 = 'mercurial-{version}-cp37-cp37m-win_amd64.whl'
+WHEEL_FILENAME_PYTHON38_X86 = 'mercurial-{version}-cp38-cp38-win32.whl'
+WHEEL_FILENAME_PYTHON38_X64 = 'mercurial-{version}-cp38-cp38-win_amd64.whl'
+
 X86_EXE_FILENAME = 'Mercurial-{version}.exe'
 X64_EXE_FILENAME = 'Mercurial-{version}-x64.exe'
 X86_MSI_FILENAME = 'mercurial-{version}-x86.msi'
@@ -300,14 +305,24 @@
     copy_latest_dist(winrm_client, '*.exe', dest_path)
 
 
-def build_wheel(winrm_client, arch: str, dest_path: pathlib.Path):
+def build_wheel(
+    winrm_client, python_version: str, arch: str, dest_path: pathlib.Path
+):
     """Build Python wheels on a remote machine.
 
     Using a WinRM client, remote commands are executed to build a Python wheel
     for Mercurial.
     """
-    print('Building Windows wheel for %s' % arch)
-    ps = get_vc_prefix(arch) + BUILD_WHEEL.format(arch=arch)
+    print('Building Windows wheel for Python %s %s' % (python_version, arch))
+
+    ps = BUILD_WHEEL.format(
+        python_version=python_version.replace(".", ""), arch=arch
+    )
+
+    # Python 2.7 requires an activated environment.
+    if python_version == "2.7":
+        ps = get_vc_prefix(arch) + ps
+
     run_powershell(winrm_client, ps)
     copy_latest_dist(winrm_client, '*.whl', dest_path)
 
@@ -356,15 +371,23 @@
 
 def resolve_wheel_artifacts(dist_path: pathlib.Path, version: str):
     return (
-        dist_path / X86_WHEEL_FILENAME.format(version=version),
-        dist_path / X64_WHEEL_FILENAME.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON27_X86.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON27_X64.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON37_X86.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON37_X64.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON38_X86.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON38_X64.format(version=version),
     )
 
 
 def resolve_all_artifacts(dist_path: pathlib.Path, version: str):
     return (
-        dist_path / X86_WHEEL_FILENAME.format(version=version),
-        dist_path / X64_WHEEL_FILENAME.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON27_X86.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON27_X64.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON37_X86.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON37_X64.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON38_X86.format(version=version),
+        dist_path / WHEEL_FILENAME_PYTHON38_X64.format(version=version),
         dist_path / X86_EXE_FILENAME.format(version=version),
         dist_path / X64_EXE_FILENAME.format(version=version),
         dist_path / X86_MSI_FILENAME.format(version=version),