add python as a first level dep and fix UB with stdout override

build.zig

@@ -68,7 +68,20 @@ pub fn build(b: *std.Build) !void {
     exe.root_module.addImport("cpython", cpython_dep.module("cpython"));
     exe.root_module.addImport("vaxis", libvaxis.module("vaxis"));
 
-    exe_options.addOption([]const u8, "lib_path", "../python/Lib");
+    // install the Lib folder from python
+    const python_dep = b.dependency("python", .{});
+    const libpython_install = b.addInstallDirectory(.{
+        .source_dir = python_dep.path("Lib"),
+        .install_dir = .{ .custom = "python" },
+        .install_subdir = "Lib",
+    });
+    exe.step.dependOn(&libpython_install.step);
+
+    exe_options.addOption(
+        []const u8,
+        "lib_path",
+        b.getInstallPath(.{ .custom = "python" }, "Lib"),
+    );
 
     const run_cmd = b.addRunArtifact(exe);
     run_cmd.step.dependOn(b.getInstallStep());

build.zig.zon

@@ -13,8 +13,10 @@
             .url = "https://github.com/Rexicon226/zig-tracer/archive/6400e066bb3849be4906f3b6e124d6c8c5a5083f.tar.gz",
             .hash = "122057453dba0b0cf6f07610d692cc7ab3f1d66defa150c936b398144812564a0c08",
         },
-        .cpython = .{
-            .path = "../zig-cpython",
+        // needs to be kept in sync with cpython dep
+        .python = .{
+            .url = "https://github.com/Rexicon226/cpython/archive/cdb93314157b15ba6ba0832f4ad7c84c11088331.tar.gz",
+            .hash = "12201233efd4fb9453166782f1beb083953b3e9cc2b347621a55482addf0714e6962",
         },
         .libgc = .{
             .url = "https://github.com/Rexicon226/zig-libgc/archive/1ea12e140ec1471af5d15dae71b225764c9747ba.tar.gz",
@@ -24,5 +26,9 @@
             .url = "https://github.com/rockorager/libvaxis/archive/c213919849114ce03def64806af546b9fc391859.tar.gz",
             .hash = "12206f2265ca2262f919ec125ff7fe15fa6f3be622806e211d7a9bd3055ba51a0908",
         },
+        .cpython = .{
+            .url = "https://github.com/Rexicon226/zig-cpython/archive/6ee418f9f7be7e811e5555f73a0335905c386914.tar.gz",
+            .hash = "122017c3777f28ab50709a456371d710e3a00c9ac82959128319ffbdfb18f1528c2a",
+        },
     },
 }

src/modules/builtins.zig

@@ -98,7 +98,7 @@ fn print(vm: *Vm, args: []const Object, maybe_kw: ?KW_Type) BuiltinError!void {
     const t = tracer.trace(@src(), "builtin-print", .{});
     defer t.end();
 
-    const stdout = vm.stdout;
+    const stdout = vm.getStdout();
     for (args, 0..) |arg, i| {
         printSafe(stdout, "{}", .{arg});
 
@@ -146,8 +146,8 @@ fn input(vm: *Vm, args: []const Object, maybe_kw: ?KW_Type) BuiltinError!void {
         const prompt = args[0];
         const prompt_string = prompt.get(.string);
 
-        const stdout = std.io.getStdOut();
-        printSafe(stdout.writer(), "{s}", .{prompt_string});
+        const stdout = vm.getStdout();
+        printSafe(stdout, "{s}", .{prompt_string});
     }
 
     const stdin = std.io.getStdIn();

src/vm/Vm.zig

@@ -56,7 +56,7 @@ crash_info: crash_report.VmContext,
 builtin_mods: std.StringHashMapUnmanaged(Object.Payload.Module) = .{},
 
 /// Default set to FD1
-stdout: std.io.AnyWriter,
+stdout_override: ?std.io.AnyWriter,
 
 /// Takes ownership of `co`.
 pub fn init(allocator: Allocator, co: CodeObject) !Vm {
@@ -69,7 +69,7 @@ pub fn init(allocator: Allocator, co: CodeObject) !Vm {
         .co = co,
         .crash_info = crash_report.prepVmContext(co),
         .stack = try std.ArrayListUnmanaged(Object).initCapacity(allocator, co.stacksize),
-        .stdout = std.io.getStdOut().writer().any(),
+        .stdout_override = null,
     };
 
     assert(vm.scopes.items.len == 0);
@@ -795,6 +795,11 @@ fn setNewCo(
     vm.co = new_co;
 }
 
+const stdout = std.io.getStdOut().writer();
+pub fn getStdout(vm: *const Vm) std.io.AnyWriter {
+    return vm.stdout_override orelse stdout.any();
+}
+
 pub fn fail(
     vm: *Vm,
     comptime fmt: []const u8,

src/vm/debug.zig

@@ -76,7 +76,7 @@ const State = struct {
                 }
 
                 const vm = state.vm;
-                vm.stdout = state.stdout.writer().any();
+                vm.stdout_override = state.stdout.writer().any();
                 vm.is_running = true;
 
                 while (vm.is_running) {