6 files changed, 69 insertions, 3 deletions
diff --git a/lib/std/Build/Step/Compile.zig b/lib/std/Build/Step/Compile.zig
index d18d8de413..504025e3d4 100644
--- a/lib/std/Build/Step/Compile.zig
+++ b/lib/std/Build/Step/Compile.zig
@@ -989,10 +989,10 @@ fn getGeneratedFilePath(compile: *Compile, comptime tag_name: []const u8, asking
     return path;
 }
 
-fn make(step: *Step, prog_node: std.Progress.Node) !void {
+fn getZigArgs(compile: *Compile) ![][]const u8 {
+    const step = &compile.step;
     const b = step.owner;
     const arena = b.allocator;
-    const compile: *Compile = @fieldParentPtr("step", step);
 
     var zig_args = ArrayList([]const u8).init(arena);
     defer zig_args.deinit();
@@ -1298,6 +1298,7 @@ fn make(step: *Step, prog_node: std.Progress.Node) !void {
             // We need to emit the --mod argument here so that the above link objects
             // have the correct parent module, but only if the module is part of
             // this compilation.
+            if (!my_responsibility) continue;
             if (cli_named_modules.modules.getIndex(dep.module)) |module_cli_index| {
                 const module_cli_name = cli_named_modules.names.keys()[module_cli_index];
                 try dep.module.appendZigProcessFlags(&zig_args, step);
@@ -1724,7 +1725,16 @@ fn make(step: *Step, prog_node: std.Progress.Node) !void {
         try zig_args.append(resolved_args_file);
     }
 
-    const maybe_output_bin_path = step.evalZigProcess(zig_args.items, prog_node) catch |err| switch (err) {
+    return try zig_args.toOwnedSlice();
+}
+
+fn make(step: *Step, prog_node: std.Progress.Node) !void {
+    const b = step.owner;
+    const compile: *Compile = @fieldParentPtr("step", step);
+
+    const zig_args = try getZigArgs(compile);
+
+    const maybe_output_bin_path = step.evalZigProcess(zig_args, prog_node) catch |err| switch (err) {
         error.NeedCompileErrorCheck => {
             assert(compile.expect_errors != null);
             try checkCompileErrors(compile);
diff --git a/test/standalone/build.zig.zon b/test/standalone/build.zig.zon
index 1e79a547e9..80e9ba046c 100644
--- a/test/standalone/build.zig.zon
+++ b/test/standalone/build.zig.zon
@@ -86,6 +86,9 @@
         .dirname = .{
             .path = "dirname",
         },
+        .dep_duplicate_module = .{
+            .path = "dep_duplicate_module",
+        },
         .empty_env = .{
             .path = "empty_env",
         },
diff --git a/test/standalone/dep_duplicate_module/build.zig b/test/standalone/dep_duplicate_module/build.zig
new file mode 100644
index 0000000000..733d49b91c
--- /dev/null
+++ b/test/standalone/dep_duplicate_module/build.zig
@@ -0,0 +1,32 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const mod = b.addModule("mod", .{
+        .root_source_file = b.path("mod.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const lib = b.addStaticLibrary(.{
+        .name = "lib",
+        .root_source_file = b.path("lib.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+    lib.root_module.addImport("mod", mod);
+
+    const exe = b.addExecutable(.{
+        .name = "app",
+        .root_source_file = b.path("main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    exe.root_module.addImport("mod", mod);
+    exe.root_module.linkLibrary(lib);
+
+    b.installArtifact(exe);
+}
diff --git a/test/standalone/dep_duplicate_module/lib.zig b/test/standalone/dep_duplicate_module/lib.zig
new file mode 100644
index 0000000000..0a44f1a8ce
--- /dev/null
+++ b/test/standalone/dep_duplicate_module/lib.zig
@@ -0,0 +1,6 @@
+const std = @import("std");
+const mod = @import("mod");
+
+export fn work(x: u32) u32 {
+    return mod.double(x);
+}
diff --git a/test/standalone/dep_duplicate_module/main.zig b/test/standalone/dep_duplicate_module/main.zig
new file mode 100644
index 0000000000..0ff26699c3
--- /dev/null
+++ b/test/standalone/dep_duplicate_module/main.zig
@@ -0,0 +1,8 @@
+const std = @import("std");
+const mod = @import("mod");
+
+extern fn work(x: u32) u32;
+
+pub fn main() !void {
+    _ = work(mod.half(25));
+}
diff --git a/test/standalone/dep_duplicate_module/mod.zig b/test/standalone/dep_duplicate_module/mod.zig
new file mode 100644
index 0000000000..019ae3be97
--- /dev/null
+++ b/test/standalone/dep_duplicate_module/mod.zig
@@ -0,0 +1,7 @@
+pub fn double(v: u32) u32 {
+    return v * 2;
+}
+
+pub fn half(v: u32) u32 {
+    return v / 2;
+}