diff --git a/ci/eval/compare/default.nix b/ci/eval/compare/default.nix
index 5807f8ef52f7..81eebcc9adb1 100644
--- a/ci/eval/compare/default.nix
+++ b/ci/eval/compare/default.nix
@@ -122,7 +122,8 @@ let
 in
 runCommand "compare"
   {
-    nativeBuildInputs = [
+    # Don't depend on -dev outputs to reduce closure size for CI.
+    nativeBuildInputs = map lib.getBin [
       jq
       (python3.withPackages (
         ps: with ps; [
diff --git a/ci/eval/default.nix b/ci/eval/default.nix
index 21285757a277..2b7f59ae6b43 100644
--- a/ci/eval/default.nix
+++ b/ci/eval/default.nix
@@ -14,10 +14,9 @@
   runCommand,
   writeShellScript,
   symlinkJoin,
-  time,
-  procps,
-  nix,
+  busybox,
   jq,
+  nix,
 }:
 
 let
@@ -48,9 +47,10 @@ let
     runCommand "attrpaths-superset.json"
       {
         src = nixpkgs;
-        nativeBuildInputs = [
+        # Don't depend on -dev outputs to reduce closure size for CI.
+        nativeBuildInputs = map lib.getBin [
+          busybox
           nix
-          time
         ];
       }
       ''
@@ -72,11 +72,11 @@ let
       # The system to evaluate.
       # Note that this is intentionally not called `system`,
       # because `--argstr system` would only be passed to the ci/default.nix file!
-      evalSystem,
+      evalSystem ? builtins.currentSystem,
       # The path to the `paths.json` file from `attrpathsSuperset`
       attrpathFile ? "${attrpathsSuperset { inherit evalSystem; }}/paths.json",
       # The number of attributes per chunk, see ./README.md for more info.
-      chunkSize,
+      chunkSize ? 5000,
       checkMeta ? true,
 
       # Don't try to eval packages marked as broken.
@@ -131,11 +131,11 @@ let
     in
     runCommand "nixpkgs-eval-${evalSystem}"
       {
-        nativeBuildInputs = [
-          nix
-          time
-          procps
+        # Don't depend on -dev outputs to reduce closure size for CI.
+        nativeBuildInputs = map lib.getBin [
+          busybox
           jq
+          nix
         ];
         env = {
           inherit evalSystem chunkSize;
@@ -160,14 +160,14 @@ let
         # Record and print stats on free memory and swap in the background
         (
           while true; do
-            availMemory=$(free -b | grep Mem | awk '{print $7}')
-            freeSwap=$(free -b | grep Swap | awk '{print $4}')
-            echo "Available memory: $(( availMemory / 1024 / 1024 )) MiB, free swap: $(( freeSwap / 1024 / 1024 )) MiB"
+            availMemory=$(free -m | grep Mem | awk '{print $7}')
+            freeSwap=$(free -m | grep Swap | awk '{print $4}')
+            echo "Available memory: $(( availMemory )) MiB, free swap: $(( freeSwap )) MiB"
 
             if [[ ! -f "$out/${evalSystem}/min-avail-memory" ]] || (( availMemory < $(<$out/${evalSystem}/min-avail-memory) )); then
               echo "$availMemory" > $out/${evalSystem}/min-avail-memory
             fi
-            if [[ ! -f $out/${evalSystem}/min-free-swap ]] || (( availMemory < $(<$out/${evalSystem}/min-free-swap) )); then
+            if [[ ! -f $out/${evalSystem}/min-free-swap ]] || (( freeSwap < $(<$out/${evalSystem}/min-free-swap) )); then
               echo "$freeSwap" > $out/${evalSystem}/min-free-swap
             fi
             sleep 4
@@ -206,7 +206,8 @@ let
     }:
     runCommand "combined-eval"
       {
-        nativeBuildInputs = [
+        # Don't depend on -dev outputs to reduce closure size for CI.
+        nativeBuildInputs = map lib.getBin [
           jq
         ];
       }