automation: set PATH when building on Windows

Sometime in the 6.2 release cycle the Windows building automation
broke. Building the wheel and even PyOxidizer based installers now fails
with:

```
Exception: PowerShell execution failed:   error: subprocess-exited-with-error
Getting requirements to build wheel did not run successfully.
exit code: 1
[1 lines of output]
Unable to find a working hg binary to extract the version from the repository tags
[end of output]
note: This error originates from a subprocess, and is likely not a problem with pip.
```

I have a hunch this is a regression from upgrading pip in 1c00777702da,
but I haven't verified this. It may not be, as PyOxidizer has its own
bundled Python/pip. So maybe it is something in `setup.py`.

contrib/automation/hgautomation/windows.py

@@ -1,539 +1,542 b''
 # windows.py - Automation specific to Windows
 #
 # Copyright 2019 Gregory Szorc <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 # no-check-code because Python 3 native.
 
 import datetime
 import os
 import paramiko
 import pathlib
 import re
 import subprocess
 import tempfile
 
 from .pypi import upload as pypi_upload
 from .winrm import run_powershell
 
 
 HG_PURGE = r'''
 $Env:PATH = "C:\hgdev\venv-bootstrap\Scripts;$Env:PATH"
 Set-Location C:\hgdev\src
 hg.exe --config extensions.purge= purge --all
 if ($LASTEXITCODE -ne 0) {
     throw "process exited non-0: $LASTEXITCODE"
 }
 Write-Output "purged Mercurial repo"
 '''
 
 HG_UPDATE_CLEAN = r'''
 $Env:PATH = "C:\hgdev\venv-bootstrap\Scripts;$Env:PATH"
 Set-Location C:\hgdev\src
 hg.exe --config extensions.purge= purge --all
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
 hg.exe update -C {revision}
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
 hg.exe log -r .
 Write-Output "updated Mercurial working directory to {revision}"
 '''.lstrip()
 
 BUILD_INNO_PYTHON3 = r'''
+$Env:PATH = "C:\hgdev\venv-bootstrap\Scripts;$Env:PATH"
 $Env:RUSTUP_HOME = "C:\hgdev\rustup"
 $Env:CARGO_HOME = "C:\hgdev\cargo"
 Set-Location C:\hgdev\src
 C:\hgdev\python37-x64\python.exe contrib\packaging\packaging.py inno --pyoxidizer-target {pyoxidizer_target} --version {version}
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
 '''
 
 
 BUILD_WHEEL = r'''
+$Env:PATH = "C:\hgdev\venv-bootstrap\Scripts;$Env:PATH"
 Set-Location C:\hgdev\src
 C:\hgdev\python{python_version}-{arch}\python.exe -m pip wheel --wheel-dir dist .
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
 '''
 
 BUILD_WIX_PYTHON3 = r'''
+$Env:PATH = "C:\hgdev\venv-bootstrap\Scripts;$Env:PATH"
 $Env:RUSTUP_HOME = "C:\hgdev\rustup"
 $Env:CARGO_HOME = "C:\hgdev\cargo"
 Set-Location C:\hgdev\src
 C:\hgdev\python37-x64\python.exe contrib\packaging\packaging.py wix --pyoxidizer-target {pyoxidizer_target} --version {version}
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
 '''
 
 
 RUN_TESTS = r'''
 C:\hgdev\MinGW\msys\1.0\bin\sh.exe --login -c "cd /c/hgdev/src/tests && /c/hgdev/{python_path}/python.exe run-tests.py {test_flags}"
 if ($LASTEXITCODE -ne 0) {{
     throw "process exited non-0: $LASTEXITCODE"
 }}
 '''
 
 
 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'
 WHEEL_FILENAME_PYTHON39_X86 = 'mercurial-{version}-cp39-cp39-win32.whl'
 WHEEL_FILENAME_PYTHON39_X64 = 'mercurial-{version}-cp39-cp39-win_amd64.whl'
 WHEEL_FILENAME_PYTHON310_X86 = 'mercurial-{version}-cp310-cp310-win32.whl'
 WHEEL_FILENAME_PYTHON310_X64 = 'mercurial-{version}-cp310-cp310-win_amd64.whl'
 
 EXE_FILENAME_PYTHON3_X86 = 'Mercurial-{version}-x86.exe'
 EXE_FILENAME_PYTHON3_X64 = 'Mercurial-{version}-x64.exe'
 
 MSI_FILENAME_PYTHON3_X86 = 'mercurial-{version}-x86.msi'
 MSI_FILENAME_PYTHON3_X64 = 'mercurial-{version}-x64.msi'
 
 MERCURIAL_SCM_BASE_URL = 'https://mercurial-scm.org/release/windows'
 
 X86_USER_AGENT_PATTERN = '.*Windows.*'
 X64_USER_AGENT_PATTERN = '.*Windows.*(WOW|x)64.*'
 
 # TODO remove Python version once Python 2 is dropped.
 EXE_PYTHON3_X86_DESCRIPTION = (
     'Mercurial {version} Inno Setup installer - x86 Windows (Python 3) '
     '- does not require admin rights'
 )
 EXE_PYTHON3_X64_DESCRIPTION = (
     'Mercurial {version} Inno Setup installer - x64 Windows (Python 3) '
     '- does not require admin rights'
 )
 MSI_PYTHON3_X86_DESCRIPTION = (
     'Mercurial {version} MSI installer - x86 Windows (Python 3) '
     '- requires admin rights'
 )
 MSI_PYTHON3_X64_DESCRIPTION = (
     'Mercurial {version} MSI installer - x64 Windows (Python 3) '
     '- requires admin rights'
 )
 
 
 def fix_authorized_keys_permissions(winrm_client, path):
     commands = [
         '$ErrorActionPreference = "Stop"',
         'Repair-AuthorizedKeyPermission -FilePath %s -Confirm:$false' % path,
         r'icacls %s /remove:g "NT Service\sshd"' % path,
     ]
 
     run_powershell(winrm_client, '\n'.join(commands))
 
 
 def synchronize_hg(hg_repo: pathlib.Path, revision: str, ec2_instance):
     """Synchronize local Mercurial repo to remote EC2 instance."""
 
     winrm_client = ec2_instance.winrm_client
 
     with tempfile.TemporaryDirectory() as temp_dir:
         temp_dir = pathlib.Path(temp_dir)
 
         ssh_dir = temp_dir / '.ssh'
         ssh_dir.mkdir()
         ssh_dir.chmod(0o0700)
 
         # Generate SSH key to use for communication.
         subprocess.run(
             [
                 'ssh-keygen',
                 '-t',
                 'rsa',
                 '-b',
                 '4096',
                 '-N',
                 '',
                 '-f',
                 str(ssh_dir / 'id_rsa'),
             ],
             check=True,
             capture_output=True,
         )
 
         # Add it to ~/.ssh/authorized_keys on remote.
         # This assumes the file doesn't already exist.
         authorized_keys = r'c:\Users\Administrator\.ssh\authorized_keys'
         winrm_client.execute_cmd(r'mkdir c:\Users\Administrator\.ssh')
         winrm_client.copy(str(ssh_dir / 'id_rsa.pub'), authorized_keys)
         fix_authorized_keys_permissions(winrm_client, authorized_keys)
 
         public_ip = ec2_instance.public_ip_address
 
         ssh_config = temp_dir / '.ssh' / 'config'
 
         with open(ssh_config, 'w', encoding='utf-8') as fh:
             fh.write('Host %s\n' % public_ip)
             fh.write('  User Administrator\n')
             fh.write('  StrictHostKeyChecking no\n')
             fh.write('  UserKnownHostsFile %s\n' % (ssh_dir / 'known_hosts'))
             fh.write('  IdentityFile %s\n' % (ssh_dir / 'id_rsa'))
 
         if not (hg_repo / '.hg').is_dir():
             raise Exception(
                 '%s is not a Mercurial repository; '
                 'synchronization not yet supported' % hg_repo
             )
 
         env = dict(os.environ)
         env['HGPLAIN'] = '1'
         env['HGENCODING'] = 'utf-8'
 
         hg_bin = hg_repo / 'hg'
 
         res = subprocess.run(
             ['python3', str(hg_bin), 'log', '-r', revision, '-T', '{node}'],
             cwd=str(hg_repo),
             env=env,
             check=True,
             capture_output=True,
         )
 
         full_revision = res.stdout.decode('ascii')
 
         args = [
             'python3',
             hg_bin,
             '--config',
             'ui.ssh=ssh -F %s' % ssh_config,
             '--config',
             'ui.remotecmd=c:/hgdev/venv-bootstrap/Scripts/hg.exe',
             # Also ensure .hgtags changes are present so auto version
             # calculation works.
             'push',
             '-f',
             '-r',
             full_revision,
             '-r',
             'file(.hgtags)',
             'ssh://%s/c:/hgdev/src' % public_ip,
         ]
 
         res = subprocess.run(args, cwd=str(hg_repo), env=env)
 
         # Allow 1 (no-op) to not trigger error.
         if res.returncode not in (0, 1):
             res.check_returncode()
 
         run_powershell(
             winrm_client, HG_UPDATE_CLEAN.format(revision=full_revision)
         )
 
         # TODO detect dirty local working directory and synchronize accordingly.
 
 
 def purge_hg(winrm_client):
     """Purge the Mercurial source repository on an EC2 instance."""
     run_powershell(winrm_client, HG_PURGE)
 
 
 def find_latest_dist(winrm_client, pattern):
     """Find path to newest file in dist/ directory matching a pattern."""
 
     res = winrm_client.execute_ps(
         r'$v = Get-ChildItem -Path C:\hgdev\src\dist -Filter "%s" '
         '| Sort-Object LastWriteTime -Descending '
         '| Select-Object -First 1\n'
         '$v.name' % pattern
     )
     return res[0]
 
 
 def copy_latest_dist(winrm_client, pattern, dest_path):
     """Copy latest file matching pattern in dist/ directory.
 
     Given a WinRM client and a file pattern, find the latest file on the remote
     matching that pattern and copy it to the ``dest_path`` directory on the
     local machine.
     """
     latest = find_latest_dist(winrm_client, pattern)
     source = r'C:\hgdev\src\dist\%s' % latest
     dest = dest_path / latest
     print('copying %s to %s' % (source, dest))
     winrm_client.fetch(source, str(dest))
 
 
 def build_inno_installer(
     winrm_client,
     arch: str,
     dest_path: pathlib.Path,
     version=None,
 ):
     """Build the Inno Setup installer on a remote machine.
 
     Using a WinRM client, remote commands are executed to build
     a Mercurial Inno Setup installer.
     """
     print('building Inno Setup installer for %s' % arch)
 
     # TODO fix this limitation in packaging code
     if not version:
         raise Exception("version string is required when building for Python 3")
 
     if arch == "x86":
         target_triple = "i686-pc-windows-msvc"
     elif arch == "x64":
         target_triple = "x86_64-pc-windows-msvc"
     else:
         raise Exception("unhandled arch: %s" % arch)
 
     ps = BUILD_INNO_PYTHON3.format(
         pyoxidizer_target=target_triple,
         version=version,
     )
 
     run_powershell(winrm_client, ps)
     copy_latest_dist(winrm_client, '*.exe', dest_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 Python %s %s' % (python_version, arch))
 
     ps = BUILD_WHEEL.format(
         python_version=python_version.replace(".", ""), arch=arch
     )
 
     run_powershell(winrm_client, ps)
     copy_latest_dist(winrm_client, '*.whl', dest_path)
 
 
 def build_wix_installer(
     winrm_client,
     arch: str,
     dest_path: pathlib.Path,
     version=None,
 ):
     """Build the WiX installer on a remote machine.
 
     Using a WinRM client, remote commands are executed to build a WiX installer.
     """
     print('Building WiX installer for %s' % arch)
 
     # TODO fix this limitation in packaging code
     if not version:
         raise Exception("version string is required when building for Python 3")
 
     if arch == "x86":
         target_triple = "i686-pc-windows-msvc"
     elif arch == "x64":
         target_triple = "x86_64-pc-windows-msvc"
     else:
         raise Exception("unhandled arch: %s" % arch)
 
     ps = BUILD_WIX_PYTHON3.format(
         pyoxidizer_target=target_triple,
         version=version,
     )
 
     run_powershell(winrm_client, ps)
     copy_latest_dist(winrm_client, '*.msi', dest_path)
 
 
 def run_tests(winrm_client, python_version, arch, test_flags=''):
     """Run tests on a remote Windows machine.
 
     ``python_version`` is a ``X.Y`` string like ``2.7`` or ``3.7``.
     ``arch`` is ``x86`` or ``x64``.
     ``test_flags`` is a str representing extra arguments to pass to
     ``run-tests.py``.
     """
     if not re.match(r'\d\.\d', python_version):
         raise ValueError(
             r'python_version must be \d.\d; got %s' % python_version
         )
 
     if arch not in ('x86', 'x64'):
         raise ValueError('arch must be x86 or x64; got %s' % arch)
 
     python_path = 'python%s-%s' % (python_version.replace('.', ''), arch)
 
     ps = RUN_TESTS.format(
         python_path=python_path,
         test_flags=test_flags or '',
     )
 
     run_powershell(winrm_client, ps)
 
 
 def resolve_wheel_artifacts(dist_path: pathlib.Path, version: str):
     return (
         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 / WHEEL_FILENAME_PYTHON39_X86.format(version=version),
         dist_path / WHEEL_FILENAME_PYTHON39_X64.format(version=version),
         dist_path / WHEEL_FILENAME_PYTHON310_X86.format(version=version),
         dist_path / WHEEL_FILENAME_PYTHON310_X64.format(version=version),
     )
 
 
 def resolve_all_artifacts(dist_path: pathlib.Path, version: str):
     return (
         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 / WHEEL_FILENAME_PYTHON39_X86.format(version=version),
         dist_path / WHEEL_FILENAME_PYTHON39_X64.format(version=version),
         dist_path / WHEEL_FILENAME_PYTHON310_X86.format(version=version),
         dist_path / WHEEL_FILENAME_PYTHON310_X64.format(version=version),
         dist_path / EXE_FILENAME_PYTHON3_X86.format(version=version),
         dist_path / EXE_FILENAME_PYTHON3_X64.format(version=version),
         dist_path / MSI_FILENAME_PYTHON3_X86.format(version=version),
         dist_path / MSI_FILENAME_PYTHON3_X64.format(version=version),
     )
 
 
 def generate_latest_dat(version: str):
     python3_x86_exe_filename = EXE_FILENAME_PYTHON3_X86.format(version=version)
     python3_x64_exe_filename = EXE_FILENAME_PYTHON3_X64.format(version=version)
     python3_x86_msi_filename = MSI_FILENAME_PYTHON3_X86.format(version=version)
     python3_x64_msi_filename = MSI_FILENAME_PYTHON3_X64.format(version=version)
 
     entries = (
         (
             '10',
             version,
             X86_USER_AGENT_PATTERN,
             '%s/%s' % (MERCURIAL_SCM_BASE_URL, python3_x86_exe_filename),
             EXE_PYTHON3_X86_DESCRIPTION.format(version=version),
         ),
         (
             '10',
             version,
             X64_USER_AGENT_PATTERN,
             '%s/%s' % (MERCURIAL_SCM_BASE_URL, python3_x64_exe_filename),
             EXE_PYTHON3_X64_DESCRIPTION.format(version=version),
         ),
         (
             '10',
             version,
             X86_USER_AGENT_PATTERN,
             '%s/%s' % (MERCURIAL_SCM_BASE_URL, python3_x86_msi_filename),
             MSI_PYTHON3_X86_DESCRIPTION.format(version=version),
         ),
         (
             '10',
             version,
             X64_USER_AGENT_PATTERN,
             '%s/%s' % (MERCURIAL_SCM_BASE_URL, python3_x64_msi_filename),
             MSI_PYTHON3_X64_DESCRIPTION.format(version=version),
         ),
     )
 
     lines = ['\t'.join(e) for e in entries]
 
     return '\n'.join(lines) + '\n'
 
 
 def publish_artifacts_pypi(dist_path: pathlib.Path, version: str):
     """Publish Windows release artifacts to PyPI."""
 
     wheel_paths = resolve_wheel_artifacts(dist_path, version)
 
     for p in wheel_paths:
         if not p.exists():
             raise Exception('%s not found' % p)
 
     print('uploading wheels to PyPI (you may be prompted for credentials)')
     pypi_upload(wheel_paths)
 
 
 def publish_artifacts_mercurial_scm_org(
     dist_path: pathlib.Path, version: str, ssh_username=None
 ):
     """Publish Windows release artifacts to mercurial-scm.org."""
     all_paths = resolve_all_artifacts(dist_path, version)
 
     for p in all_paths:
         if not p.exists():
             raise Exception('%s not found' % p)
 
     client = paramiko.SSHClient()
     client.load_system_host_keys()
     # We assume the system SSH configuration knows how to connect.
     print('connecting to mercurial-scm.org via ssh...')
     try:
         client.connect('mercurial-scm.org', username=ssh_username)
     except paramiko.AuthenticationException:
         print('error authenticating; is an SSH key available in an SSH agent?')
         raise
 
     print('SSH connection established')
 
     print('opening SFTP client...')
     sftp = client.open_sftp()
     print('SFTP client obtained')
 
     for p in all_paths:
         dest_path = '/var/www/release/windows/%s' % p.name
         print('uploading %s to %s' % (p, dest_path))
 
         with p.open('rb') as fh:
             data = fh.read()
 
         with sftp.open(dest_path, 'wb') as fh:
             fh.write(data)
             fh.chmod(0o0664)
 
     latest_dat_path = '/var/www/release/windows/latest.dat'
 
     now = datetime.datetime.utcnow()
     backup_path = dist_path / (
         'latest-windows-%s.dat' % now.strftime('%Y%m%dT%H%M%S')
     )
     print('backing up %s to %s' % (latest_dat_path, backup_path))
 
     with sftp.open(latest_dat_path, 'rb') as fh:
         latest_dat_old = fh.read()
 
     with backup_path.open('wb') as fh:
         fh.write(latest_dat_old)
 
     print('writing %s with content:' % latest_dat_path)
     latest_dat_content = generate_latest_dat(version)
     print(latest_dat_content)
 
     with sftp.open(latest_dat_path, 'wb') as fh:
         fh.write(latest_dat_content.encode('ascii'))
 
 
 def publish_artifacts(
     dist_path: pathlib.Path,
     version: str,
     pypi=True,
     mercurial_scm_org=True,
     ssh_username=None,
 ):
     """Publish Windows release artifacts.
 
     Files are found in `dist_path`. We will look for files with version string
     `version`.
 
     `pypi` controls whether we upload to PyPI.
     `mercurial_scm_org` controls whether we upload to mercurial-scm.org.
     """
     if pypi:
         publish_artifacts_pypi(dist_path, version)
 
     if mercurial_scm_org:
         publish_artifacts_mercurial_scm_org(
             dist_path, version, ssh_username=ssh_username
         )