gnu: python-attrs: Update to 18.2.0.

* gnu/packages/python.scm (python-attrs): Update to 18.2.0.
[arguments]: New field.
[native-inputs]: Add PYTHON-PYMPLER.
(python-attrs-bootstrap): Stay on version 17.4.0.

gnu/packages/python.scm

@@ -11122,17 +11122,36 @@ and bit flag values.")
 (define-public python-attrs
   (package
     (name "python-attrs")
-    (version "17.4.0")
+    (version "18.2.0")
     (source (origin
               (method url-fetch)
               (uri (pypi-uri "attrs" version))
               (sha256
                (base32
-                "1jafnn1kzd6qhxgprhx6y6ik1r5m2rilx25syzcmq03azp660y8w"))))
+                "0s9ydh058wmmf5v391pym877x4ahxg45dw6a0w4c7s5wgpigdjqh"))))
     (build-system python-build-system)
+    (arguments
+     `(#:modules ((guix build utils)
+                  (guix build python-build-system)
+                  (ice-9 ftw)
+                  (srfi srfi-1)
+                  (srfi srfi-26))
+       #:phases (modify-phases %standard-phases
+                  (replace 'check
+                    (lambda _
+                      (let ((cwd (getcwd)))
+                        (setenv "PYTHONPATH"
+                                (string-append
+                                 cwd "/build/"
+                                 (find (cut string-prefix? "lib" <>)
+                                       (scandir (string-append cwd "/build")))
+                                 ":"
+                                 (getenv "PYTHONPATH")))
+                        (invoke "python" "-m" "pytest")))))))
     (native-inputs
      `(("python-coverage" ,python-coverage)
        ("python-hypothesis" ,python-hypothesis)
+       ("python-pympler" ,python-pympler)
        ("python-pytest" ,python-pytest)
        ("python-six" ,python-six)
        ("python-sphinx" ,python-sphinx)
@@ -11151,6 +11170,15 @@ protocols.")
   (package
     (inherit python-attrs)
     (name "python-attrs-bootstrap")
+    ;; Keep this on a fixed version so python-attrs can be updated without
+    ;; triggering a mass-rebuild.  FIXME: Update this in the next rebuild cycle.
+    (version "17.4.0")
+    (source (origin
+              (method url-fetch)
+              (uri (pypi-uri "attrs" version))
+              (sha256
+               (base32
+                "1jafnn1kzd6qhxgprhx6y6ik1r5m2rilx25syzcmq03azp660y8w"))))
     (native-inputs `())
     (arguments `(#:tests? #f))))