josm: minor cleanups

- Use `makeWrapper` to generate wrapper script.

- Use `buildCommand` instead of explicit phases.`

pkgs/applications/misc/josm/default.nix

···
-{ fetchurl, stdenv, makeDesktopItem, unzip, bash, jre8 }:
+{ fetchurl, stdenv, makeDesktopItem, makeWrapper, unzip, bash, jre8 }:
 
 stdenv.mkDerivation rec {
   name = "josm-${version}";
···
     sha256 = "0lpz4yzkvjpn5g36nibrkh773jnlkiqj6lghsx69i86h0xfb7gqf";
   };
 
-  phases = [ "installPhase" ];
-
-  buildInputs = [ jre8 ];
+  buildInputs = [ jre8 makeWrapper ];
 
   desktopItem = makeDesktopItem {
     name = "josm";
···
     categories = "Education;Geoscience;Maps;";
   };
 
-  installPhase = ''
+  buildCommand = ''
     mkdir -p $out/bin $out/share/java
     cp -v $src $out/share/java/josm.jar
-    cat > $out/bin/josm <<EOF
-    #!${bash}/bin/bash
-    exec ${jre8}/bin/java -jar $out/share/java/josm.jar "\$@"
-    EOF
-    chmod 755 $out/bin/josm
+
+    makeWrapper ${jre8}/bin/java $out/bin/josm \
+      --add-flags "-jar $out/share/java/josm.jar"
 
     mkdir -p $out/share/applications
     cp $desktopItem/share/applications"/"* $out/share/applications