gnu: python-flake8: Update to 3.6.0.

* gnu/packages/check.scm (python-hypothesis)[native-inputs]: Change
PYTHON-FLAKE8 to PYTHON-FLAKE8-3.5.
* gnu/packages/python.scm (python-flake8, python2-flake8): Rename to ...
(python-flake8-3.5, python2-flake8-3.5): ... this.
(python-flake8, python2-flake8): New public variables.

gnu/packages/check.scm

@@ -1425,7 +1425,8 @@ normally the case.")
                 "1rshs1japfmwgar98yrkq4hg4z2q76hlnq7w2n3lfbjnscn1jd9b"))))
     (build-system python-build-system)
     (native-inputs
-     `(("python-flake8" ,python-flake8)
+     `(;; FIXME: Change to python-flake8 in the next rebuild cycle.
+       ("python-flake8" ,python-flake8-3.5)
        ("python-pytest" ,python-pytest-bootstrap)))
     (propagated-inputs
      `(("python-attrs" ,python-attrs-bootstrap)

gnu/packages/python.scm

@@ -5826,7 +5826,9 @@ complexity of Python source code.")
 (define-public python2-pyflakes-0.8.1
   (package-with-python2 python-pyflakes-0.8.1))
 
-(define-public python-flake8
+;; This package is used by hypothesis which has thousands of dependent packages.
+;; FIXME: Consolidate this with "python-flake8" below in the next rebuild cycle.
+(define-public python-flake8-3.5
   (package
     (name "python-flake8")
     (version "3.5.0")
@@ -5872,17 +5874,45 @@ PEP8_PLUGIN('break_before_binary_operator'),"))
       "The modular source code checker: pep8, pyflakes and co")
     (description
       "Flake8 is a wrapper around PyFlakes, pep8 and python-mccabe.")
-    (properties `((python2-variant . ,(delay python2-flake8))))
+    (properties `((python2-variant . ,(delay python2-flake8-3.5))))
     (license license:expat)))
 
-(define-public python2-flake8
-  (let ((base (package-with-python2 (strip-python2-variant python-flake8))))
+(define-public python2-flake8-3.5
+  (let ((base (package-with-python2 (strip-python2-variant python-flake8-3.5))))
     (package (inherit base)
       (propagated-inputs
        `(("python2-configparser" ,python2-configparser)
          ("python2-enum34" ,python2-enum34)
           ,@(package-propagated-inputs base))))))
 
+;; Version 3.5.0 has compatibility issues with Pyflakes 2.0, so we need
+;; this newer version.  Keep it as a separate variable for now to avoid
+;; rebuilding "python-hypothesis"; this should be removed in the next
+;; rebuild cycle.
+(define-public python-flake8
+  (package
+    (inherit python-flake8-3.5)
+    (version "3.6.0")
+    (source (origin
+              (method url-fetch)
+              (uri (pypi-uri "flake8" version))
+              (sha256
+               (base32
+                "0w0nprx22rbvrrkbfx9v5jc5gskbm08g219l7r8wai8zfswgadba"))))
+    (arguments
+     (substitute-keyword-arguments (package-arguments python-flake8-3.5)
+       ((#:phases phases)
+        `(modify-phases ,phases
+           (delete 'delete-broken-test)
+           (delete 'fix-problem-with-pycodestyle)))))
+    (properties `((python2-variant . ,(delay python2-flake8))))))
+
+(define-public python2-flake8
+  (let ((base (package-with-python2 (strip-python2-variant python-flake8))))
+    (package (inherit base)
+             (propagated-inputs
+              (package-propagated-inputs python2-flake8-3.5)))))
+
 ;; python-hacking requires flake8 <2.6.0.
 (define-public python-flake8-2.5
   (package