Merge branch 'master' into feature/re-vendor-sadface

1 files changed, 31 insertions, 27 deletions

diff --git a/setuptools/sandbox.py b/setuptools/sandbox.py
index 817a3afa..f99c13c4 100755
--- a/setuptools/sandbox.py
+++ b/setuptools/sandbox.py
@@ -7,6 +7,7 @@ import itertools
 import re
 import contextlib
 import pickle
+import textwrap
 
 from setuptools.extern import six
 from setuptools.extern.six.moves import builtins, map
@@ -215,7 +216,7 @@ def _needs_hiding(mod_name):
     >>> _needs_hiding('Cython')
     True
     """
-    pattern = re.compile('(setuptools|pkg_resources|distutils|Cython)(\.|$)')
+    pattern = re.compile(r'(setuptools|pkg_resources|distutils|Cython)(\.|$)')
     return bool(pattern.match(mod_name))
 
 
@@ -248,11 +249,9 @@ def run_setup(setup_script, args):
                 setup_script.encode(sys.getfilesystemencoding())
             )
 
-            def runner():
+            with DirectorySandbox(setup_dir):
                 ns = dict(__file__=dunder_file, __name__='__main__')
                 _execfile(setup_script, ns)
-
-            DirectorySandbox(setup_dir).run(runner)
         except SystemExit as v:
             if v.args and v.args[0]:
                 raise
@@ -274,21 +273,24 @@ class AbstractSandbox:
         for name in self._attrs:
             setattr(os, name, getattr(source, name))
 
+    def __enter__(self):
+        self._copy(self)
+        if _file:
+            builtins.file = self._file
+        builtins.open = self._open
+        self._active = True
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self._active = False
+        if _file:
+            builtins.file = _file
+        builtins.open = _open
+        self._copy(_os)
+
     def run(self, func):
         """Run 'func' under os sandboxing"""
-        try:
-            self._copy(self)
-            if _file:
-                builtins.file = self._file
-            builtins.open = self._open
-            self._active = True
+        with self:
             return func()
-        finally:
-            self._active = False
-            if _file:
-                builtins.file = _file
-            builtins.open = _open
-            self._copy(_os)
 
     def _mk_dual_path_wrapper(name):
         original = getattr(_os, name)
@@ -391,7 +393,7 @@ class DirectorySandbox(AbstractSandbox):
 
     _exception_patterns = [
         # Allow lib2to3 to attempt to save a pickled grammar object (#121)
-        '.*lib2to3.*\.pickle$',
+        r'.*lib2to3.*\.pickle$',
     ]
     "exempt writing to paths that match the pattern"
 
@@ -476,16 +478,18 @@ WRITE_FLAGS = functools.reduce(
 class SandboxViolation(DistutilsError):
     """A setup script attempted to modify the filesystem outside the sandbox"""
 
-    def __str__(self):
-        return """SandboxViolation: %s%r %s
-
-The package setup script has attempted to modify files on your system
-that are not within the EasyInstall build area, and has been aborted.
+    tmpl = textwrap.dedent("""
+        SandboxViolation: {cmd}{args!r} {kwargs}
 
-This package cannot be safely installed by EasyInstall, and may not
-support alternate installation locations even if you run its setup
-script by hand.  Please inform the package's author and the EasyInstall
-maintainers to find out if a fix or workaround is available.""" % self.args
+        The package setup script has attempted to modify files on your system
+        that are not within the EasyInstall build area, and has been aborted.
 
+        This package cannot be safely installed by EasyInstall, and may not
+        support alternate installation locations even if you run its setup
+        script by hand.  Please inform the package's author and the EasyInstall
+        maintainers to find out if a fix or workaround is available.
+        """).lstrip()
 
-#
+    def __str__(self):
+        cmd, args, kwargs = self.args
+        return self.tmpl.format(**locals())