fix: change the pip runner string based on a pip version check

aws_lambda_builders/workflows/python_pip/compat.py

@@ -8,15 +8,23 @@ def pip_import_string(python_exe):
     cmd = [
         python_exe,
         "-c",
-        "import pip; assert int(pip.__version__.split('.')[0]) <= 9"
+        "import pip; print(pip.__version__)"
     ]
-    p = os_utils.popen(cmd,stdout=os_utils.pipe, stderr=os_utils.pipe)
-    p.communicate()
+    p = os_utils.popen(cmd, stdout=os_utils.pipe, stderr=os_utils.pipe)
+    stdout, stderr = p.communicate()
+    pip_version = stdout.decode('utf-8').strip()
+    pip_major_version = int(pip_version.split('.')[0])
+    pip_minor_version = int(pip_version.split('.')[1])
+
     # Pip moved its internals to an _internal module in version 10.
     # In order to be compatible with version 9 which has it at at the
     # top level we need to figure out the correct import path here.
-    if p.returncode == 0:
+    if pip_major_version == 9:
         return 'from pip import main'
+    # Pip changed their import structure again in 19.3
+    # https://github.com/pypa/pip/commit/09fd200
+    elif pip_major_version >= 19 and pip_minor_version >= 3:
+        return 'from pip._internal.main import main'
     else:
         return 'from pip._internal import main'
 

tests/unit/workflows/python_pip/test_packager.py

@@ -1,5 +1,6 @@
 import sys
 from collections import namedtuple
+from unittest import TestCase
 
 import mock
 import pytest
@@ -70,7 +71,7 @@ def osutils():
 
 class FakePopen(object):
     def __init__(self, rc, out, err):
-        self.returncode = 0
+        self.returncode = rc
         self._out = out
         self._err = err
 
@@ -303,14 +304,24 @@ def test_inject_unknown_error_if_no_stderr(self, pip_factory):
         assert str(einfo.value) == 'Unknown error'
 
 
-class TestSubprocessPip(object):
+class TestSubprocessPip(TestCase):
     def test_does_use_custom_pip_import_string(self):
         fake_osutils = FakePopenOSUtils([FakePopen(0, '', '')])
         expected_import_statement = 'foobarbaz'
         pip = SubprocessPip(osutils=fake_osutils,
-                            import_string=expected_import_statement)
+                            import_string=expected_import_statement,
+                            python_exe=sys.executable)
         pip.main(['--version'])
 
         pip_execution_string = fake_osutils.popens[0][0][0][2]
         import_statement = pip_execution_string.split(';')[1].strip()
         assert import_statement == expected_import_statement
+
+    def test_check_pip_runner_string_pip(self):
+        fake_osutils = FakePopenOSUtils([FakePopen(0, '', '')])
+        pip = SubprocessPip(osutils=fake_osutils,
+                            python_exe=sys.executable)
+        pip.main(['--version'])
+
+        pip_runner_string = fake_osutils.popens[0][0][0][2].split(";")[-1:][0]
+        self.assertIn("main", pip_runner_string)