From: Daira Hopwood <daira@jacaranda.org>
Date: Sat, 2 May 2015 21:26:39 +0000 (+0100)
Subject: Retire the setup_requires hack in cases where it isn't needed (and can cause build... 
X-Git-Url: https://git.rkrishnan.org/components/architecture.txt?a=commitdiff_plain;h=b1a7cbbbc8fa5939bec96c074684680b34f204db;p=tahoe-lafs%2Ftahoe-lafs.git

Retire the setup_requires hack in cases where it isn't needed (and can cause build problems). refs #2286

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
---

diff --git a/setup.py b/setup.py
index 5f687853..ea89195a 100644
--- a/setup.py
+++ b/setup.py
@@ -113,23 +113,6 @@ trove_classifiers=[
     ]
 
 
-setup_requires = []
-
-# Nevow imports itself when building, which causes Twisted and zope.interface
-# to be imported. We need to make sure that the versions of Twisted and
-# zope.interface used at build time satisfy Nevow's requirements. If not
-# then there are two problems:
-#  - prior to Nevow v0.9.33, Nevow didn't declare its dependency on Twisted
-#    in a way that enabled setuptools to satisfy that requirement at
-#    build time.
-#  - some versions of zope.interface, e.g. v3.6.4, are incompatible with
-#    Nevow, and we need to avoid those both at build and run-time.
-#
-# This only matters when compatible versions of Twisted and zope.interface
-# are not already installed. Retire this hack when
-# https://bugs.launchpad.net/nevow/+bug/812537 has been fixed.
-setup_requires += [req for req in install_requires if req.startswith('Twisted') or req.startswith('zope.interface')]
-
 # We no longer have any requirements specific to tests.
 tests_require=[]
 
diff --git a/src/allmydata/_auto_deps.py b/src/allmydata/_auto_deps.py
index e8e2b172..4e5c40bc 100644
--- a/src/allmydata/_auto_deps.py
+++ b/src/allmydata/_auto_deps.py
@@ -121,12 +121,23 @@ if not hasattr(sys, 'frozen'):
 # already installed.
 # <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2028>
 #
+# When the fallback is used we also need to work around the fact
+# that Nevow imports itself when building, which causes Twisted
+# and zope.interface to be imported; therefore, we need to set
+# setup_requires to make sure that the versions of Twisted and
+# zope.interface used at build time satisfy Nevow's requirements.
+#
 # In cases where this fallback isn't needed, we prefer Nevow >= 0.11.1
 # which can be installed using pip, and Twisted >= 13.0.0 which
-# Nevow 0.11.1 depends on.
+# Nevow 0.11.1 depends on. In this case we should *not* use the
+# setup_requires hack, because if we do then the build will break
+# when Twisted < 13.0.0 is already installed (even though it could
+# have succeeded by building a later version under support/ ).
+#
 # <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2032>
 # <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2249>
 # <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2291>
+# <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2286>
 
 _use_old_Twisted_and_Nevow = False
 if sys.platform == "win32":
@@ -140,11 +151,14 @@ if _use_old_Twisted_and_Nevow:
         "Twisted >= 11.1.0, <= 12.1.0",
         "Nevow >= 0.9.33, <= 0.10",
     ]
+    setup_requires = [req for req in install_requires if req.startswith('Twisted')
+                                                      or req.startswith('zope.interface')]
 else:
     install_requires += [
         "Twisted >= 13.0.0",
         "Nevow >= 0.11.1",
     ]
+    setup_requires = []
 
 
 # * pyOpenSSL is required in order for foolscap to provide secure connections.