diff --git a/hacking/cargo-manifest-management/Makefile b/hacking/cargo-manifest-management/Makefile
index d8cc21a8a..0b47e7a74 100644
--- a/hacking/cargo-manifest-management/Makefile
+++ b/hacking/cargo-manifest-management/Makefile
@@ -4,10 +4,8 @@
 # SPDX-License-Identifier: BSD-2-Clause
 #
 
-project_root := ../..
-
 run_script := \
-	script=$$(nix-build -A script --no-out-link) && $$script --root $(project_root)
+	script=$$(nix-build -A script --no-out-link) && $$script
 
 .PHONY: none
 none:
diff --git a/hacking/cargo-manifest-management/execute_plan.py b/hacking/cargo-manifest-management/execute_plan.py
index db664792b..efbc84186 100644
--- a/hacking/cargo-manifest-management/execute_plan.py
+++ b/hacking/cargo-manifest-management/execute_plan.py
@@ -16,19 +16,18 @@
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('--plan', type=Path)
-    parser.add_argument('--root', type=Path)
     parser.add_argument('--just-check', default=False, action=argparse.BooleanOptionalAction)
     args = parser.parse_args()
 
     with args.plan.open() as f:
         plan = json.load(f)
 
-    run(plan, args.root, args.just_check)
+    run(plan, args.just_check)
 
 
-def run(plan, root, just_check):
-    for relative_manifest_path, v in plan.items():
-        manifest_path = root / relative_manifest_path
+def run(plan, just_check):
+    for manifest_path, v in plan.items():
+        manifest_path = Path(manifest_path)
         src = Path(v['src'])
         just_check_equivalence = v['justEnsureEquivalence']
 
diff --git a/hacking/cargo-manifest-management/manual-manifests.nix b/hacking/cargo-manifest-management/manual-manifests.nix
index c6c4924ca..85c330655 100644
--- a/hacking/cargo-manifest-management/manual-manifests.nix
+++ b/hacking/cargo-manifest-management/manual-manifests.nix
@@ -4,11 +4,15 @@
 # SPDX-License-Identifier: BSD-2-Clause
 #
 
-{
-  # "virtio-drivers" = "tmp/virtio-drivers";
-  # "mbedtls" = "tmp/rust-mbedtls/mbedtls";
-  # "mbedtls-sys-auto" = "tmp/rust-mbedtls/mbedtls-sys";
-  # "mbedtls-platform-support" = "tmp/rust-mbedtls/mbedtls-platform-support";
-  # "embedded-fat" = "tmp/rust-embedded-fat";
-  # "volatile" = "tmp/volatile";
+let
+
+  relativeToWorkspaceRoot = relativePath: "${toString ../..}/${relativePath}";
+
+in {
+  # "virtio-drivers" = relativeToWorkspaceRoot "tmp/virtio-drivers";
+  # "mbedtls" = relativeToWorkspaceRoot "tmp/rust-mbedtls/mbedtls";
+  # "mbedtls-sys-auto" = relativeToWorkspaceRoot "tmp/rust-mbedtls/mbedtls-sys";
+  # "mbedtls-platform-support" = relativeToWorkspaceRoot "tmp/rust-mbedtls/mbedtls-platform-support";
+  # "embedded-fat" = relativeToWorkspaceRoot "tmp/rust-embedded-fat";
+  # "volatile" = relativeToWorkspaceRoot "tmp/volatile";
 }
diff --git a/hacking/cargo-manifest-management/workspace.nix b/hacking/cargo-manifest-management/workspace.nix
index 4113161d0..e3f89337f 100644
--- a/hacking/cargo-manifest-management/workspace.nix
+++ b/hacking/cargo-manifest-management/workspace.nix
@@ -22,20 +22,17 @@ let
     in
       scanDirForFilesWithName dirFilter "Cargo.nix" workspaceRoot;
 
-  genrateManifest = absolutePath:
+  genrateManifest = cargoNixAbsolutePath:
     let
-      relativePath =
-        pathBetween
-          workspaceRoot
-          (builtins.dirOf absolutePath);
+      absolutePath = builtins.dirOf cargoNixAbsolutePath;
       manifestExpr = callManifest {
-        inherit relativePath;
-        f = import absolutePath;
+        inherit absolutePath;
+        f = import cargoNixAbsolutePath;
       };
       parsed = parseManifestExpr manifestExpr;
       inherit (parsed) manifestValue frontmatter justEnsureEquivalence;
     in {
-      inherit relativePath manifestValue frontmatter justEnsureEquivalence;
+      inherit absolutePath manifestValue frontmatter justEnsureEquivalence;
       packageName = manifestValue.package.name or null;
       packageVersion = manifestValue.package.version or null;
       manifestTOML = renderManifest {
@@ -65,19 +62,19 @@ let
         inherit (elaboratedNix) frontmatter justEnsureEquivalence;
       };
 
-  callManifest = { relativePath, f }:
+  callManifest = { absolutePath, f }:
     let
       bespokeScope = manifestScope // {
-        localCrates = mkDeps relativePath;
+        localCrates = mkDeps absolutePath;
       };
       args = builtins.intersectAttrs (lib.functionArgs f) bespokeScope;
     in
       f args;
 
-  mkDeps = relativePath:
+  mkDeps = absolutePath:
     let
-      rel = pathBetween relativePath;
-      generated = lib.mapAttrs (_: manifest: { path = rel manifest.relativePath; }) generatedManifestsByPackageName;
+      rel = pathBetween absolutePath;
+      generated = lib.mapAttrs (_: manifest: { path = rel manifest.absolutePath; }) generatedManifestsByPackageName;
       manual = lib.mapAttrs (_: otherPath: { path = rel otherPath; }) manualManifests;
     in
       generated // manual;
@@ -90,7 +87,7 @@ let
         (manifest: lib.optional (manifest.packageName != null) (lib.nameValuePair manifest.packageName manifest)));
 
   plan = lib.listToAttrs (lib.forEach generatedManifestsList (manifest: {
-    name = "${manifest.relativePath}${lib.optionalString (manifest.relativePath != "") "/"}Cargo.toml";
+    name = "${manifest.absolutePath}/Cargo.toml";
     value = {
       src = manifest.manifestTOML;
       inherit (manifest) justEnsureEquivalence;
@@ -105,7 +102,10 @@ let
   '';
 
   # for manual inspection, useful for debugging this script
-  links = linkFarm "crates" (lib.mapAttrs (_: v: v.src) plan);
+  links = linkFarm "crates"
+    (lib.mapAttrs'
+      (absolutePath: v: lib.nameValuePair "root/${absolutePath}" v.src)
+      plan);
 
 in {
   inherit script;