icdiff: use python3

pkgs/tools/text/icdiff/default.nix

@@ -1,6 +1,6 @@
-{ lib, fetchFromGitHub, pythonPackages }:
+{ lib, fetchFromGitHub, python3Packages, bash, git, less }:
 
-pythonPackages.buildPythonApplication rec {
+python3Packages.buildPythonApplication rec {
   pname = "icdiff";
   version = "1.9.5";
 
@@ -11,6 +11,20 @@ pythonPackages.buildPythonApplication rec {
     sha256 = "080v8h09pv8qwplin4kwfm0kmqjwdqjfxbpcdrv16sv4hwfwl5qd";
   };
 
+  checkInputs = [
+    bash
+    git
+    less
+  ];
+
+  # error: could not lock config file /homeless-shelter/.gitconfig: No such file or directory
+  doCheck = false;
+
+  checkPhase = ''
+    patchShebangs test.sh
+    ./test.sh ${python3Packages.python.interpreter}
+  '';
+
   meta = with lib; {
     homepage = "https://www.jefftk.com/icdiff";
     description = "Side-by-side highlighted command line diffs";