Cmds {install,wheel} should return proper error code

The `pip` executable was returning a successful status code (`0`) when
trying to install new packages with existing previous build directories.

Conflicts:
	tests/functional/test_install_cleanup.py
	tests/functional/test_wheel.py

pip/basecommand.py

@@ -11,10 +11,11 @@ import optparse
 from pip.log import logger
 from pip.download import urlopen
 from pip.exceptions import (BadCommand, InstallationError, UninstallationError,
-                            CommandError)
+                            CommandError, PreviousBuildDirError)
 from pip.backwardcompat import StringIO
 from pip.baseparser import ConfigOptionParser, UpdatingDefaultsHelpFormatter
-from pip.status_codes import SUCCESS, ERROR, UNKNOWN_ERROR, VIRTUALENV_NOT_FOUND
+from pip.status_codes import (SUCCESS, ERROR, UNKNOWN_ERROR, VIRTUALENV_NOT_FOUND,
+                              PREVIOUS_BUILD_DIR_ERROR)
 from pip.util import get_prog
 
 
@@ -136,6 +137,12 @@ class Command(object):
             # and when it is done, isinstance is not needed anymore
             if isinstance(status, int):
                 exit = status
+        except PreviousBuildDirError:
+            e = sys.exc_info()[1]
+            logger.fatal(str(e))
+            logger.info('Exception information:\n%s' % format_exc())
+            store_log = True
+            exit = PREVIOUS_BUILD_DIR_ERROR
         except (InstallationError, UninstallationError):
             e = sys.exc_info()[1]
             logger.fatal(str(e))

pip/commands/install.py

@@ -252,7 +252,8 @@ class InstallCommand(Command):
                 requirement_set.create_bundle(self.bundle_filename)
                 logger.notify('Created bundle in %s' % self.bundle_filename)
         except PreviousBuildDirError:
-            return
+            options.no_clean = True
+            raise
         finally:
             # Clean up
             if (not options.no_clean) and ((not options.no_install) or options.download_dir):

pip/commands/wheel.py

@@ -151,8 +151,8 @@ class WheelCommand(Command):
                 )
             wb.build()
         except PreviousBuildDirError:
-            return
+            options.no_clean = True
+            raise
         finally:
             if not options.no_clean:
                 requirement_set.cleanup_files()
-

pip/req.py

@@ -1067,16 +1067,13 @@ class RequirementSet(object):
                     # inconsistencies are logged later, but do not fail the
                     # installation.
                     elif os.path.exists(os.path.join(location, 'setup.py')):
-                        msg = textwrap.dedent("""
+                        raise PreviousBuildDirError(textwrap.dedent("""
                           pip can't proceed with requirement '%s' due to a pre-existing build directory.
                            location: %s
                           This is likely due to a previous installation that failed.
                           pip is being responsible and not assuming it can delete this.
                           Please delete it and try again.
-                        """ % (req_to_install, location))
-                        e = PreviousBuildDirError(msg)
-                        logger.fatal(msg)
-                        raise e
+                        """ % (req_to_install, location)))
                     else:
                         ## FIXME: this won't upgrade when there's an existing package unpacked in `location`
                         if req_to_install.url is None:

pip/status_codes.py

@@ -2,4 +2,5 @@ SUCCESS = 0
 ERROR = 1
 UNKNOWN_ERROR = 2
 VIRTUALENV_NOT_FOUND = 3
+PREVIOUS_BUILD_DIR_ERROR = 4
 NO_MATCHES_FOUND = 23

tests/functional/test_install_cleanup.py

@@ -5,6 +5,8 @@ from tests.lib import (tests_data, reset_env, run_pip, pip_install_local,
                             write_file, mkdir, path_to_url, find_links)
 from tests.lib.local_repos import local_checkout
 from tests.lib.path import Path
+from pip.locations import write_delete_marker_file
+from pip.status_codes import PREVIOUS_BUILD_DIR_ERROR
 
 
 def test_cleanup_after_install():
@@ -139,7 +141,10 @@ def test_cleanup_prevented_upon_build_dir_exception():
     env = reset_env()
     build = env.venv_path/'build'/'simple'
     os.makedirs(build)
+    write_delete_marker_file(env.venv_path/'build')
     write_file("setup.py", "#", dest=build)
     result = run_pip('install', '-f', find_links, '--no-index', 'simple', expect_error=True)
+
+    assert result.returncode == PREVIOUS_BUILD_DIR_ERROR
     assert "pip can't proceed" in result.stdout, result.stdout
     assert exists(build)

tests/functional/test_wheel.py

@@ -7,6 +7,8 @@ from os.path import exists
 from nose import SkipTest
 from pip import wheel
 from pip.download import path_to_url as path_to_url_d
+from pip.locations import write_delete_marker_file
+from pip.status_codes import PREVIOUS_BUILD_DIR_ERROR
 from tests.lib import tests_data, reset_env, run_pip, pyversion_nodot, write_file, path_to_url, find_links, pip_install_local
 
 
@@ -98,3 +100,21 @@ def test_pip_wheel_source_deps():
     assert "Successfully built source" in result.stdout, result.stdout
 
 
+def test_pip_wheel_fail_cause_of_previous_build_dir():
+    """Test when 'pip wheel' tries to install a package that has a previous build directory"""
+
+    env = reset_env()
+    pip_install_local('wheel')
+
+    # Given that I have a previous build dir of the `simple` package
+    build = env.venv_path / 'build' / 'simple'
+    os.makedirs(build)
+    write_delete_marker_file(env.venv_path / 'build')
+    write_file("setup.py", "#", dest=build)
+
+    # When I call pip trying to install things again
+    result = run_pip('wheel', '--no-index', '--find-links=%s' % find_links, 'simple==3.0', expect_error=True)
+
+    # Then I see that the error code is the right one
+    assert result.returncode == PREVIOUS_BUILD_DIR_ERROR
+