diff --git a/build.zig b/build.zig
index ad6f87d..e969b99 100644
--- a/build.zig
+++ b/build.zig
@@ -12,8 +12,8 @@ fn setupLinks(step: *builds.LibExeObjStep) void {
     step.linkSystemLibrary("GraphicsMagickWand");
     step.linkSystemLibrary("GraphicsMagick");
 
-    step.addIncludePath("/usr/include/GraphicsMagick");
-    step.addIncludePath("/usr/include");
+    step.addIncludePath(.{ .path = "/usr/include/GraphicsMagick" });
+    step.addIncludePath(.{ .path = "/usr/include" });
 
     const possible_lilv_include_dirs = [_][]const u8{
         "/usr/include/lilv-0/lilv",
@@ -32,7 +32,7 @@ fn setupLinks(step: *builds.LibExeObjStep) void {
         found_any_lilv = true;
 
         std.debug.print("found lilv at '{s}'\n", .{possible_lilv_dir});
-        step.addIncludePath(possible_lilv_dir);
+        step.addIncludePath(.{ .path = possible_lilv_dir });
     }
 
     if (!found_any_lilv) {
@@ -42,22 +42,34 @@ fn setupLinks(step: *builds.LibExeObjStep) void {
 }
 
 pub fn build(b: *Builder) void {
-    const mode = b.standardReleaseOptions();
-    const exe = b.addExecutable("scritcher", "src/main.zig");
-    exe.setBuildMode(mode);
-    exe.install();
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
 
+    const exe = b.addExecutable(.{
+        .name = "scritcher",
+        .root_source_file = .{ .path = "src/main.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
     setupLinks(exe);
+    b.installArtifact(exe);
 
-    const test_obj_step = b.addTest("src/main.zig");
-    setupLinks(test_obj_step);
+    const run_cmd = b.addRunArtifact(exe);
 
-    const run_cmd = exe.run();
-    run_cmd.step.dependOn(b.getInstallStep());
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
 
     const run_step = b.step("run", "Run the app");
     run_step.dependOn(&run_cmd.step);
 
-    const test_step = b.step("test", "Run tests");
-    test_step.dependOn(&test_obj_step.step);
+    const test_step = b.addTest(.{
+        .root_source_file = .{ .path = "src/main.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+    setupLinks(test_step);
+    const run_unit_tests = b.addRunArtifact(test_step);
+    const test_cmd = b.step("test", "run unit tests");
+    test_cmd.dependOn(&run_unit_tests.step);
 }
diff --git a/src/image.zig b/src/image.zig
index 47be1cd..3905ea5 100644
--- a/src/image.zig
+++ b/src/image.zig
@@ -26,7 +26,7 @@ pub fn sopen(
     mode: i32,
     fmt: *c.SF_INFO,
 ) !*c.SNDFILE {
-    var cstr_path = try std.cstr.addNullByte(allocator, path);
+    var cstr_path = try allocator.dupeZ(u8, path);
     defer allocator.free(cstr_path);
 
     var file = c.sf_open(cstr_path.ptr, mode, fmt);
@@ -321,7 +321,7 @@ pub const Image = struct {
         // now, for each param for the plugin, we find its port, and set
         // the value for the port there.
         for (params.items) |param| {
-            var sym_cstr = try std.cstr.addNullByte(self.allocator, param.sym);
+            var sym_cstr = try self.allocator.dupeZ(u8, param.sym);
             defer self.allocator.free(sym_cstr);
 
             var sym = c.lilv_new_string(ctx.world, sym_cstr.ptr);
diff --git a/src/lang.zig b/src/lang.zig
index 9f85d0f..b18b0fb 100644
--- a/src/lang.zig
+++ b/src/lang.zig
@@ -496,7 +496,8 @@ pub const CommandList = struct {
                 }
             }
 
-            self.list.allocator.destroy(cmd_ptr);
+            //TODO this is ian invalid free
+            //self.list.allocator.destroy(cmd_ptr);
         }
         self.list.deinit();
     }
@@ -537,7 +538,7 @@ pub const Lang = struct {
     fn parseCommandArguments(
         self: *@This(),
         comptime command_struct: type,
-        tok_it: *std.mem.SplitIterator(u8),
+        tok_it: *std.mem.SplitIterator(u8, .sequence),
         commands: *CommandList,
     ) !void {
         // Based on the command struct fields, we can parse the arguments.
@@ -638,7 +639,7 @@ pub const Lang = struct {
             if (std.mem.startsWith(u8, stmt, "#")) continue;
 
             // TODO better tokenizer instead of just tokenize(" ")...maybe????
-            var tok_it = std.mem.split(u8, stmt, " ");
+            var tok_it = std.mem.splitSequence(u8, stmt, " ");
 
             var cmd_opt = tok_it.next();
             if (cmd_opt == null) {
diff --git a/src/magick.zig b/src/magick.zig
index c6adf3c..e79f513 100644
--- a/src/magick.zig
+++ b/src/magick.zig
@@ -38,7 +38,7 @@ fn magickLoad(image: *Image) !MagickContext {
     var mctx = try MagickContext.init();
     errdefer mctx.deinit();
 
-    var curpath = try std.cstr.addNullByte(image.allocator, image.curpath);
+    var curpath = try image.allocator.dupeZ(u8, image.curpath);
     defer image.allocator.free(curpath);
 
     log.debug("loading '{s}'", .{curpath});
@@ -53,7 +53,7 @@ fn magickSave(image: *Image, wand: *mc.MagickWand) !void {
     const allocator = image.allocator;
 
     var tmpnam = try images.temporaryName(allocator);
-    var c_tmpnam = try std.cstr.addNullByte(allocator, tmpnam);
+    var c_tmpnam = try allocator.dupeZ(u8, tmpnam);
     defer allocator.free(c_tmpnam);
 
     log.debug("\tmagick: saving to '{s}'..", .{c_tmpnam});
diff --git a/src/main.zig b/src/main.zig
index 7b7b66b..7563392 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -29,11 +29,7 @@ fn copyCommandToHeap(allocator: std.mem.Allocator, command: langs.Command, compt
     const casted = command.cast(CommandStruct).?;
     var heap_cmd = try allocator.create(CommandStruct);
 
-    @memcpy(
-        @as([*]u8, @ptrCast(&heap_cmd)),
-        @as([*]const u8, @ptrCast(&casted)),
-        @sizeOf(CommandStruct),
-    );
+    heap_cmd.* = casted.*;
 
     return &heap_cmd.base;
 }
diff --git a/src/plugin.zig b/src/plugin.zig
index 57f8059..f5f6517 100644
--- a/src/plugin.zig
+++ b/src/plugin.zig
@@ -131,7 +131,7 @@ pub const RunContext = struct {
 };
 
 pub fn makeContext(allocator: std.mem.Allocator, plugin_uri: []const u8) !Context {
-    const cstr_plugin_uri = try std.cstr.addNullByte(allocator, plugin_uri);
+    const cstr_plugin_uri = try allocator.dupeZ(u8, plugin_uri);
     defer allocator.free(cstr_plugin_uri);
 
     var world: *c.LilvWorld = c.lilv_world_new().?;
diff --git a/src/runner.zig b/src/runner.zig
index 739a95f..0eea50b 100644
--- a/src/runner.zig
+++ b/src/runner.zig
@@ -152,7 +152,7 @@ pub const Runner = struct {
 
         while (try it.next()) |entry| {
             switch (entry.kind) {
-                .File => blk: {
+                .file => blk: {
                     if (!std.mem.startsWith(u8, entry.name, starts_with)) break :blk {};
 
                     // we want to get the N in x_gN.ext
@@ -215,7 +215,7 @@ pub const Runner = struct {
         const rotate_cmd = cmd.cast(lang.Command.Rotate).?;
 
         var image = try self.getImage();
-        var c_bgfill = try std.cstr.addNullByte(self.allocator, rotate_cmd.bgfill);
+        var c_bgfill = try self.allocator.dupeZ(u8, rotate_cmd.bgfill);
         defer self.allocator.free(c_bgfill);
 
         try magick.runRotate(image, rotate_cmd.deg, c_bgfill);