gnu: Add python-caniusepython3.

* gnu/packages/python-xyz.scm (python-caniusepython3): New variable.

gnu/packages/python-xyz.scm

@@ -1354,6 +1354,46 @@ (define-public python-can
 sending and receiving messages on a CAN bus.")
     (license license:lgpl3+)))
 
+(define-public python-caniusepython3
+  (package
+    (name "python-caniusepython3")
+    (version "7.2.0")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (pypi-uri "caniusepython3" version))
+        (sha256
+          (base32
+            "0a755444ln38j8d7xb3yw0wzpd0mjrzfn6zqvsh06nw1vdaq4l28"))))
+    (build-system python-build-system)
+    (arguments
+     `(#:phases (modify-phases %standard-phases
+                  (add-after 'unpack 'relax-requirements
+                    (lambda _
+                      (substitute* "setup.py"
+                        ;; These are for compatibility with Python 2.
+                        ((".*'argparse', 'backports.functools_lru_cache',.*")
+                         ""))
+                      (substitute* "dev_requirements.txt"
+                        ((".*pylint.*") "")) ;not actually required
+                      #t))
+                  (replace 'check
+                    (lambda _
+                      (invoke "py.test" "-k" "not NetworkTests"))))))
+    (propagated-inputs
+      `(("python-distlib" ,python-distlib)
+        ("python-packaging" ,python-packaging)
+        ("python-requests" ,python-requests)))
+    (native-inputs
+     `(("python-mock" ,python-mock)
+       ("python-pytest" ,python-pytest)))
+    (home-page "https://github.com/brettcannon/caniusepython3")
+    (synopsis "Check for Python 3-incompatible Python libraries")
+    (description "The @command{caniusepython3} command scans your project and
+reports the Python 3-incompatible libraries it found.  It can also be used as
+a library.")
+    (license license:asl2.0)))
+
 (define-public python-diskcache
   (package
     (name "python-diskcache")