dist: re-implement `fetch_build_egg` to use pip

1 files changed, 129 insertions, 0 deletions

diff --git a/setuptools/installer.py b/setuptools/installer.py
new file mode 100644
index 00000000..35bc3cc5
--- /dev/null
+++ b/setuptools/installer.py
@@ -0,0 +1,129 @@
+import glob
+import os
+import subprocess
+import sys
+from distutils import log
+from distutils.errors import DistutilsError
+
+import pkg_resources
+from setuptools.command.easy_install import easy_install
+from setuptools.wheel import Wheel
+
+from .py31compat import TemporaryDirectory
+
+
+def _legacy_fetch_build_egg(dist, req):
+    """Fetch an egg needed for building.
+
+    Legacy path using EasyInstall.
+    """
+    tmp_dist = dist.__class__({'script_args': ['easy_install']})
+    opts = tmp_dist.get_option_dict('easy_install')
+    opts.clear()
+    opts.update(
+        (k, v)
+        for k, v in dist.get_option_dict('easy_install').items()
+        if k in (
+            # don't use any other settings
+            'find_links', 'site_dirs', 'index_url',
+            'optimize', 'site_dirs', 'allow_hosts',
+        ))
+    if dist.dependency_links:
+        links = dist.dependency_links[:]
+        if 'find_links' in opts:
+            links = opts['find_links'][1] + links
+        opts['find_links'] = ('setup', links)
+    install_dir = dist.get_egg_cache_dir()
+    cmd = easy_install(
+        tmp_dist, args=["x"], install_dir=install_dir,
+        exclude_scripts=True,
+        always_copy=False, build_directory=None, editable=False,
+        upgrade=False, multi_version=True, no_report=True, user=False
+    )
+    cmd.ensure_finalized()
+    return cmd.easy_install(req)
+
+
+def fetch_build_egg(dist, req):
+    """Fetch an egg needed for building.
+
+    Use pip/wheel to fetch/build a wheel."""
+    # Check pip is available.
+    try:
+        pkg_resources.get_distribution('pip')
+    except pkg_resources.DistributionNotFound:
+        dist.announce(
+            'WARNING: The pip package is not available, falling back '
+            'to EasyInstall for handling setup_requires/test_requires; '
+            'this is deprecated and will be removed in a future version.'
+            , log.WARN
+        )
+        return _legacy_fetch_build_egg(dist, req)
+    # Warn if wheel is not.
+    try:
+        pkg_resources.get_distribution('wheel')
+    except pkg_resources.DistributionNotFound:
+        dist.announce('WARNING: The wheel package is not available.', log.WARN)
+    if not isinstance(req, pkg_resources.Requirement):
+        req = pkg_resources.Requirement.parse(req)
+    # Take easy_install options into account, but do not override relevant
+    # pip environment variables (like PIP_INDEX_URL or PIP_QUIET); they'll
+    # take precedence.
+    opts = dist.get_option_dict('easy_install')
+    if 'allow_hosts' in opts:
+        raise DistutilsError('the `allow-hosts` option is not supported '
+                             'when using pip to install requirements.')
+    if 'PIP_QUIET' in os.environ or 'PIP_VERBOSE' in os.environ:
+        quiet = False
+    else:
+        quiet = True
+    if 'PIP_INDEX_URL' in os.environ:
+        index_url = None
+    elif 'index_url' in opts:
+        index_url = opts['index_url'][1]
+    else:
+        index_url = None
+    if 'find_links' in opts:
+        find_links = opts['find_links'][1][:]
+    else:
+        find_links = []
+    if dist.dependency_links:
+        find_links.extend(dist.dependency_links)
+    eggs_dir = os.path.realpath(dist.get_egg_cache_dir())
+    environment = pkg_resources.Environment()
+    for egg_dist in pkg_resources.find_distributions(eggs_dir):
+        if egg_dist in req and environment.can_add(egg_dist):
+            return egg_dist
+    with TemporaryDirectory() as tmpdir:
+        cmd = [
+            sys.executable, '-m', 'pip',
+            '--disable-pip-version-check',
+            'wheel', '--no-deps',
+            '-w', tmpdir,
+        ]
+        if quiet:
+            cmd.append('--quiet')
+        if index_url is not None:
+            cmd.extend(('--index-url', index_url))
+        if find_links is not None:
+            for link in find_links:
+                cmd.extend(('--find-links', link))
+        # If requirement is a PEP 508 direct URL, directly pass
+        # the URL to pip, as `req @ url` does not work on the
+        # command line.
+        if req.url:
+            cmd.append(req.url)
+        else:
+            cmd.append(str(req))
+        try:
+            subprocess.check_call(cmd)
+        except subprocess.CalledProcessError as e:
+            raise DistutilsError(str(e))
+        wheel = Wheel(glob.glob(os.path.join(tmpdir, '*.whl'))[0])
+        dist_location = os.path.join(eggs_dir, wheel.egg_name())
+        wheel.install_as_egg(dist_location)
+        dist_metadata = pkg_resources.PathMetadata(
+            dist_location, os.path.join(dist_location, 'EGG-INFO'))
+        dist = pkg_resources.Distribution.from_filename(
+            dist_location, metadata=dist_metadata)
+        return dist