gnu: python2-argcomplete: Fix build.

* gnu/packages/python-xyz.scm (python2-argcomplete)[arguments]: Add phase to
set HOME variable.
[native-inputs]: Add python2-importlib-metadata.
(python-argcomplete)[properties]: Record python2-variant.

gnu/packages/python-xyz.scm

@@ -14637,10 +14637,23 @@ (define-public python-argcomplete
 particularly useful for programs with many options or sub-parsers that can
 dynamically suggest completions; for example, when browsing resources over the
 network.")
-    (license license:asl2.0)))
+    (license license:asl2.0)
+    (properties `((python2-variant . ,(delay python2-argcomplete))))))
 
 (define-public python2-argcomplete
-  (package-with-python2 python-argcomplete))
+  (let ((variant (package-with-python2
+                  (strip-python2-variant python-argcomplete))))
+    (package
+      (inherit variant)
+      (arguments
+       (substitute-keyword-arguments (package-arguments variant)
+         ((#:phases phases '%standard-phases)
+          `(modify-phases ,phases
+             (add-after 'unpack 'set-my-HOME
+               (lambda _ (setenv "HOME" "/tmp")))))))
+      (native-inputs
+       `(("python2-importlib-metadata" ,python2-importlib-metadata)
+         ,@(package-native-inputs variant))))))
 
 (define-public python-csscompressor
   (package