diff --git a/dotnet/fuzz/BUILD.bazel b/dotnet/fuzz/BUILD.bazel
index ac2b2d02b..7de7897d5 100644
--- a/dotnet/fuzz/BUILD.bazel
+++ b/dotnet/fuzz/BUILD.bazel
@@ -1,13 +1,27 @@
 load("@rules_cc//cc:defs.bzl", "cc_binary")
 load("@rules_dx//libs/starlark:fuzz.bzl", "dx_fuzz_binary")
 load("@rules_dx//quality:fixtures.bzl", "real_source_target")
+load("@rules_dx//rust/rules:defs.bzl", "rust_binary")
+
+_SUPPORTED = select({
+    "@platforms//os:linux": [],
+    "//conditions:default": ["@platforms//:incompatible"],
+})
+
+rust_binary(
+    name = "instrument",
+    srcs = ["instrument/main.rs"],
+    crate_name = "instrument",
+    crate_root = "instrument/main.rs",
+    visibility = ["//visibility:public"],
+)
 
 cc_binary(
     name = "libfuzzer_dotnet_bin",
     srcs = ["@dx_libfuzzer_dotnet//:libfuzzer-dotnet.cc"],
     copts = ["-fsanitize=fuzzer"],
     linkopts = ["-fsanitize=fuzzer"],
-    target_compatible_with = ["@platforms//os:linux"],
+    target_compatible_with = _SUPPORTED,
     testonly = True,
     visibility = ["//visibility:private"],
 )
@@ -15,7 +29,7 @@ cc_binary(
 dx_fuzz_binary(
     name = "libfuzzer_dotnet",
     binary = ":libfuzzer_dotnet_bin",
-    target_compatible_with = ["@platforms//os:linux"],
+    target_compatible_with = _SUPPORTED,
     testonly = True,
     visibility = ["//visibility:public"],
 )
diff --git a/dotnet/fuzz/instrument/main.rs b/dotnet/fuzz/instrument/main.rs
new file mode 100644
index 000000000..0afbf596f
--- /dev/null
+++ b/dotnet/fuzz/instrument/main.rs
@@ -0,0 +1,31 @@
+//! Copies an assembly and runs SharpFuzz on the copy: `instrument <sharpfuzz> <input> <output>`.
+
+use std::process::{Command, ExitCode};
+use std::{env, fs};
+
+fn main() -> ExitCode {
+    let args: Vec<String> = env::args().skip(1).collect();
+    let [sharpfuzz, input, output] = args.as_slice() else {
+        eprintln!("usage: instrument <sharpfuzz> <input> <output>");
+        return ExitCode::from(2);
+    };
+    if let Err(err) = fs::copy(input, output).and_then(|_| {
+        let mut perms = fs::metadata(output)?.permissions();
+        perms.set_readonly(false);
+        fs::set_permissions(output, perms)
+    }) {
+        eprintln!("instrument: copying {input} to {output}: {err}");
+        return ExitCode::from(1);
+    }
+    match Command::new(sharpfuzz).arg(output).status() {
+        Ok(status) if status.success() => ExitCode::SUCCESS,
+        Ok(status) => {
+            eprintln!("instrument: sharpfuzz failed: {status}");
+            ExitCode::from(1)
+        }
+        Err(err) => {
+            eprintln!("instrument: running {sharpfuzz}: {err}");
+            ExitCode::from(1)
+        }
+    }
+}
diff --git a/families/dotnet/MODULE.bazel.lock b/families/dotnet/MODULE.bazel.lock
index 9b4551caf..fcef354fd 100644
--- a/families/dotnet/MODULE.bazel.lock
+++ b/families/dotnet/MODULE.bazel.lock
@@ -257,6 +257,8 @@
     "https://bcr.bazel.build/modules/gcc_toolchain/0.13.0/MODULE.bazel": "8912be8684729c2814e922aa3555d163d1c6e7dbf620e72753fe44f3761250e4",
     "https://bcr.bazel.build/modules/gcc_toolchain/0.13.0/source.json": "41e8693ad56244dde548f7711126deda72eeff630f66f5e2d8403227d4a78097",
     "https://bcr.bazel.build/modules/google_benchmark/1.8.2/MODULE.bazel": "a70cf1bba851000ba93b58ae2f6d76490a9feb74192e57ab8e8ff13c34ec50cb",
+    "https://bcr.bazel.build/modules/google_benchmark/1.9.5/MODULE.bazel": "8a85cfd90b1e45e6e68f1aa2aa9efce3c04add57df732571d7fd54c07e7c5143",
+    "https://bcr.bazel.build/modules/google_benchmark/1.9.5/source.json": "0bd357fd9db30ee31d5eb4c78b1086ce3d79b4423ce76de19e8a2fa7b2fa2e10",
     "https://bcr.bazel.build/modules/googletest/1.14.0.bcr.1/MODULE.bazel": "22c31a561553727960057361aa33bf20fb2e98584bc4fec007906e27053f80c6",
     "https://bcr.bazel.build/modules/googletest/1.14.0/MODULE.bazel": "cfbcbf3e6eac06ef9d85900f64424708cc08687d1b527f0ef65aa7517af8118f",
     "https://bcr.bazel.build/modules/googletest/1.15.2/MODULE.bazel": "6de1edc1d26cafb0ea1a6ab3f4d4192d91a312fd2d360b63adaa213cd00b2108",
@@ -269,6 +271,8 @@
     "https://bcr.bazel.build/modules/jq.bzl/0.4.0/source.json": "52ec7530c4618e03f634b30ff719814a68d7d39c235938b7aa2abbfe1eb1c52c",
     "https://bcr.bazel.build/modules/jsoncpp/1.9.6.bcr.2/MODULE.bazel": "64f508885f907ac2518039b3d0c5c1703a8f6137d9f5d635067ba93d33c2670a",
     "https://bcr.bazel.build/modules/jsoncpp/1.9.6.bcr.2/source.json": "13199fa0a267ca46814e9e6ab313a71890c8f1822e57376fdc23a2d2cd384051",
+    "https://bcr.bazel.build/modules/libpfm/4.11.0.bcr.1/MODULE.bazel": "e5362dadc90aab6724c83a2cc1e67cbed9c89a05d97fb1f90053c8deb1e445c8",
+    "https://bcr.bazel.build/modules/libpfm/4.11.0.bcr.1/source.json": "0646414d9037f8aad148781dd760bec90b0b25ac12fda5e03f8aadbd6b9c61e6",
     "https://bcr.bazel.build/modules/libpfm/4.11.0/MODULE.bazel": "45061ff025b301940f1e30d2c16bea596c25b176c8b6b3087e92615adbd52902",
     "https://bcr.bazel.build/modules/libxml2/2.15.3/MODULE.bazel": "a6bffafd8aa8b0c13eaa4bf25d55be188ec8548549395f03e98c39bab264adaa",
     "https://bcr.bazel.build/modules/libxml2/2.15.4/MODULE.bazel": "8d0bca5635a3ba19dddd0fcf0578b032f3c127f597e7f6b24cec3462bf10b824",
@@ -417,6 +421,8 @@
     "https://bcr.bazel.build/modules/rules_robolectric/4.14.1.2/source.json": "37c10335f2361c337c5c1f34ed36d2da70534c23088062b33a8bdaab68aa9dea",
     "https://bcr.bazel.build/modules/rules_rust/0.75.0/MODULE.bazel": "77452ad75faf65400abc8d0956033d5732c68d39478c9ac064288d3f484f6e34",
     "https://bcr.bazel.build/modules/rules_rust/0.75.0/source.json": "6205a2156646606f99828f217931f4cd5c68f3ada35916dab6601020358bfc63",
+    "https://bcr.bazel.build/modules/rules_rust_prost/0.75.0/MODULE.bazel": "352c97c54b4938acaae4f5be9cf380845d56ce6f062cf161f78059764f7d901a",
+    "https://bcr.bazel.build/modules/rules_rust_prost/0.75.0/source.json": "fdd8bb6bd5fca6d0f672a2438312016e91c8010fdd9c9355a8eec4f503aa5ac5",
     "https://bcr.bazel.build/modules/rules_rust_wasm_bindgen/0.75.0/MODULE.bazel": "2da21af41a035b2c603b2b8fe768d63746df1bae69fadd2d762c0436cd601ac8",
     "https://bcr.bazel.build/modules/rules_rust_wasm_bindgen/0.75.0/source.json": "f0ce711d9162d4fda731e58d2939358d70bc35ac641c9890f998e6852842cec2",
     "https://bcr.bazel.build/modules/rules_scala/7.4.1/MODULE.bazel": "74174791015794a463fb0f1e5b68d281dbb64d0afea01a539b21abe922eab79d",
@@ -17586,7 +17592,7 @@
     "@@rules_zig+//zig:extensions.bzl%zig": {
       "general": {
         "bzlTransitiveDigest": "vTeQKV6Xl5RuIpCwuarKlx1FwNYsPvKFOklJop5h/mI=",
-        "usagesDigest": "G3RaphUrcukF6Utq5kIh8yMCfhYZTf1FZHFUaUmNuy0=",
+        "usagesDigest": "QF0FP4iBd3UL3eOAQ/3YQ/7Y7gdmVPz2aHt0+5zCriE=",
         "recordedInputs": [
           "REPO_MAPPING:rules_zig+,bazel_skylib bazel_skylib+",
           "REPO_MAPPING:rules_zig+,bazel_tools bazel_tools",
@@ -17997,22 +18003,6 @@
     "@@aspect_tools_telemetry+//:extension.bzl%telemetry": {
       "notice_version": "3"
     },
-    "@@rules_dx+//ocaml/toolchain:repos.bzl%ocaml": {
-      "691408b00730fcedbd3e30ccdb42c388a83fd304/astring.0.8.5": {
-        "needs": [
-          "ocamlfind",
-          "ocamlbuild",
-          "topkg"
-        ],
-        "sha256": "865692630c07c3ab87c66cdfc2734c0fdfc9c34a57f8e89ffec7c7d15e7a70fa",
-        "src": "https://erratique.ch/software/astring/releases/astring-0.8.5.tbz"
-      },
-      "691408b00730fcedbd3e30ccdb42c388a83fd304/either.1.0.0": {
-        "needs": [],
-        "sha256": "bf674de3312dee7b7215f07df1e8a96eb3d679164b8a918cdd95b8d97e505884",
-        "src": "https://github.com/mirage/either/releases/download/1.0.0/either-1.0.0.tbz"
-      }
-    },
     "@@rules_go+//go:extensions.bzl%go_sdk": {
       "1.22.4": {
         "aix_ppc64": [
diff --git a/families/dotnet/csharp/rules/sharpfuzz.bzl b/families/dotnet/csharp/rules/sharpfuzz.bzl
index 47fab83f0..2c4f8ed7b 100644
--- a/families/dotnet/csharp/rules/sharpfuzz.bzl
+++ b/families/dotnet/csharp/rules/sharpfuzz.bzl
@@ -8,7 +8,10 @@ SHARPFUZZ = [
     Label("@paket.main//sharpfuzz"),
 ]
 
-_LINUX = ["@platforms//os:linux"]
+_SUPPORTED = select({
+    "@platforms//os:linux": [],
+    "//conditions:default": ["@platforms//:incompatible"],
+})
 
 DxSharpFuzzInfo = provider(
     doc = "A target's runtime info with first-party assemblies instrumented by SharpFuzz.",
@@ -29,12 +32,12 @@ def _aspect_impl(target, ctx):
     libs = []
     for dll in runtime.libs:
         copy = ctx.actions.declare_file("{}_sharpfuzz/{}".format(ctx.label.name, dll.basename))
-        ctx.actions.run_shell(
+        ctx.actions.run(
             inputs = [dll],
             outputs = [copy],
+            executable = ctx.executable._instrument,
             tools = [ctx.executable._sharpfuzz],
-            command = 'cp "$1" "$2" && chmod u+w "$2" && "$3" "$2"',
-            arguments = [dll.path, copy.path, ctx.executable._sharpfuzz.path],
+            arguments = [ctx.executable._sharpfuzz.path, dll.path, copy.path],
             mnemonic = "SharpFuzzInstrument",
             progress_message = "Instrumenting %{output} with SharpFuzz",
         )
@@ -61,6 +64,11 @@ dx_sharpfuzz_aspect = aspect(
     implementation = _aspect_impl,
     attr_aspects = ["deps"],
     attrs = {
+        "_instrument": attr.label(
+            default = Label("@rules_dx//dotnet/fuzz:instrument"),
+            executable = True,
+            cfg = "exec",
+        ),
         "_sharpfuzz": attr.label(
             default = Label("@paket.main//sharpfuzz.commandline/tools:sharpfuzz"),
             executable = True,
@@ -111,7 +119,7 @@ def sharpfuzz_fuzz(name, binary, srcs, deps, visibility, tags, kwargs):
         )
         instrumented.append(":" + wrapped)
     kwargs = dict(kwargs)
-    kwargs["target_compatible_with"] = kwargs.get("target_compatible_with", _LINUX)
+    kwargs["target_compatible_with"] = kwargs.get("target_compatible_with", _SUPPORTED)
     binary(
         name = name,
         srcs = srcs,