diff --git a/.github/actions/cache-go-dependencies/action.yaml b/.github/actions/cache-go-dependencies/action.yaml
index 7ea1be17ccc9d..c6cfa9e31778f 100644
--- a/.github/actions/cache-go-dependencies/action.yaml
+++ b/.github/actions/cache-go-dependencies/action.yaml
@@ -5,6 +5,10 @@ inputs:
     description: Whether this job saves caches on pushes to the default branch.
     required: false
     default: 'true'
+  key-suffix:
+    description: Extra suffix for cache keys (use to distinguish matrix entries that share github.job).
+    required: false
+    default: ''
 runs:
   using: composite
   steps:
@@ -15,42 +19,38 @@ runs:
         echo "GOMODCACHE=$(go env GOMODCACHE)" >> "$GITHUB_OUTPUT"
         echo "GOARCH=$(go env GOARCH)" >> "$GITHUB_OUTPUT"
         echo "TAG=${{ github.sha }}" >> "$GITHUB_OUTPUT"
+        suffix="${{ inputs.key-suffix }}"
+        echo "KEY_SUFFIX=${suffix:+-$suffix}" >> "$GITHUB_OUTPUT"
       shell: bash
 
-    # Save caches only on pushes to the default branch.
-    # All other events (PRs, etc.) restore only.
-    - name: Cache Go Dependencies (save)
-      if: inputs.save == 'true' && (github.event_name == 'push' && github.ref_name == github.event.repository.default_branch)
+    # Temporarily always save for testing cache effectiveness.
+    - name: Cache Go Dependencies
       uses: actions/cache@v5
       with:
         path: ${{ steps.cache-paths.outputs.GOMODCACHE }}
         key: go-mod-v1-${{ hashFiles('**/go.sum') }}
         restore-keys: go-mod-v1-
 
-    - name: Cache Go Dependencies (restore)
-      if: ${{ !(inputs.save == 'true' && (github.event_name == 'push' && github.ref_name == github.event.repository.default_branch)) }}
-      uses: actions/cache/restore@v5
-      with:
-        path: ${{ steps.cache-paths.outputs.GOMODCACHE }}
-        key: go-mod-v1-${{ hashFiles('**/go.sum') }}
-        restore-keys: go-mod-v1-
-
-    - name: Cache Go Build (save)
-      if: inputs.save == 'true' && (github.event_name == 'push' && github.ref_name == github.event.repository.default_branch)
+    - name: Cache Go Build
       uses: actions/cache@v5
       with:
         path: ${{ steps.cache-paths.outputs.GOCACHE }}
-        key: go-build-v1-${{ github.job }}-${{ steps.cache-paths.outputs.GOARCH }}-${{ steps.cache-paths.outputs.TAG }}
-        restore-keys: go-build-v1-${{ github.job }}-${{ steps.cache-paths.outputs.GOARCH }}-
-
-    - name: Cache Go Build (restore)
-      if: ${{ !(inputs.save == 'true' && (github.event_name == 'push' && github.ref_name == github.event.repository.default_branch)) }}
-      uses: actions/cache/restore@v5
-      with:
-        path: ${{ steps.cache-paths.outputs.GOCACHE }}
-        key: go-build-v1-${{ github.job }}-${{ steps.cache-paths.outputs.GOARCH }}-${{ steps.cache-paths.outputs.TAG }}
-        restore-keys: go-build-v1-${{ github.job }}-${{ steps.cache-paths.outputs.GOARCH }}-
+        key: go-build-v1-${{ github.job }}${{ steps.cache-paths.outputs.KEY_SUFFIX }}-${{ steps.cache-paths.outputs.GOARCH }}-${{ steps.cache-paths.outputs.TAG }}
+        restore-keys: go-build-v1-${{ github.job }}${{ steps.cache-paths.outputs.KEY_SUFFIX }}-${{ steps.cache-paths.outputs.GOARCH }}-
 
     - name: Download Go modules
       run: make deps --always-make
       shell: bash
+
+    - name: Stabilize file mtimes for Go test cache
+      run: |
+        # Go's test cache validates inputs by (path, size, mtime) — NOT content.
+        # git checkout sets all mtimes to "now", which differs between CI runs,
+        # causing every test to miss the cache. Setting a fixed mtime makes the
+        # test cache hit across runs when file content hasn't changed.
+        #
+        # Risk: if a non-.go testdata file changes content but not size between
+        # commits, the test cache could return a stale result. This is extremely
+        # rare and Go's own test cache has the same inherent limitation.
+        git ls-files -z | xargs -0 touch -t 200101010000
+      shell: bash
diff --git a/.github/workflows/unit-tests.yaml b/.github/workflows/unit-tests.yaml
index 770f30321edf1..a64bf5bfff738 100644
--- a/.github/workflows/unit-tests.yaml
+++ b/.github/workflows/unit-tests.yaml
@@ -42,6 +42,8 @@ jobs:
 
     - name: Cache Go dependencies
       uses: ./.github/actions/cache-go-dependencies
+      with:
+        key-suffix: ${{ matrix.gotags }}
 
     - name: Go Unit Tests
       run: ${{ matrix.gotags }} make go-unit-tests
@@ -122,6 +124,8 @@ jobs:
 
     - name: Cache Go dependencies
       uses: ./.github/actions/cache-go-dependencies
+      with:
+        key-suffix: ${{ matrix.gotags }}
 
     - name: Is Postgres ready
       run: pg_isready -h 127.0.0.1
@@ -182,6 +186,8 @@ jobs:
 
     - name: Cache Go dependencies
       uses: ./.github/actions/cache-go-dependencies
+      with:
+        key-suffix: ${{ matrix.gotags }}
 
     - name: Is Postgres ready
       run: pg_isready -h 127.0.0.1
@@ -303,6 +309,8 @@ jobs:
 
     - name: Cache Go dependencies
       uses: ./.github/actions/cache-go-dependencies
+      with:
+        key-suffix: ${{ matrix.gotags }}
 
     - uses: ./.github/actions/handle-tagged-build
 
@@ -403,6 +411,8 @@ jobs:
 
     - name: Cache Go dependencies
       uses: ./.github/actions/cache-go-dependencies
+      with:
+        key-suffix: ${{ matrix.gotags }}
 
     - name: Login to Quay.io
       uses: docker/login-action@v4
diff --git a/pkg/mathutil/mod.go b/pkg/mathutil/mod.go
index 2456fae02e52e..c9c8736a17f7e 100644
--- a/pkg/mathutil/mod.go
+++ b/pkg/mathutil/mod.go
@@ -12,3 +12,11 @@ func Mod(a, b int) int {
 	}
 	return r
 }
+
+// MinInt returns the smaller of a and b.
+func MinInt(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
diff --git a/scripts/go-tool.sh b/scripts/go-tool.sh
index 4d96666e4a775..00f5ed13753cd 100755
--- a/scripts/go-tool.sh
+++ b/scripts/go-tool.sh
@@ -12,6 +12,7 @@ die() {
 }
 
 RACE="${RACE:-false}"
+REPO_ROOT="${SCRIPT_DIR}/.."
 
 x_defs=()
 x_def_errors=()
@@ -26,7 +27,7 @@ while read -r line || [[ -n "$line" ]]; do
 	else
 		die "Malformed status.sh output line ${line}"
 	fi
-done < <(cd "${SCRIPT_DIR}/.."; ./status.sh)
+done < <(cd "${REPO_ROOT}"; ./status.sh)
 
 while read -r line || [[ -n "$line" ]]; do
 	if [[ "$line" =~ ^[[:space:]]*$ ]]; then
@@ -41,33 +42,68 @@ while read -r line || [[ -n "$line" ]]; do
 		[[ -n "${!varname}" ]] || x_def_errors+=(
 			"Variable ${go_var} defined in ${go_file}:${go_line} references status var ${status_var} that is not part of the status.sh output"
 		)
-		go_package="$(cd "${SCRIPT_DIR}/.."; go list -e "./$(dirname "$go_file")")"
+		go_package="$(cd "${REPO_ROOT}"; go list -e "./$(dirname "$go_file")")"
 
 		x_defs+=(-X "\"${go_package}.${go_var}=${!varname}\"")
 	fi
-done < <(git -C "${SCRIPT_DIR}/.." grep -n '//XDef:' -- '*.go')
+done < <(git -C "${REPO_ROOT}" grep -n '//XDef:' -- '*.go')
 if [[ "${#x_def_errors[@]}" -gt 0 ]]; then
 	printf >&2 "%s\n" "${x_def_errors[@]}"
 	exit 1
 fi
 
-ldflags=("${x_defs[@]}")
+# Build ldflags: full version for builds, stable base tag for tests.
+# Go includes -X ldflags in the link ActionID (exec.go:1404), so per-commit
+# values (MainVersion, GitShortSha) invalidate the test result cache.
+# Using a stable base tag for tests keeps test ActionIDs constant across commits.
+build_ldflags=("${x_defs[@]}")
+
+BASE_VERSION="$(cd "${REPO_ROOT}"; git describe --tags --abbrev=0 --exclude '*-nightly-*' 2>/dev/null || echo "")"
+if [[ -n "$BASE_VERSION" ]]; then
+  version_pkg="$(cd "${REPO_ROOT}"; go list -e ./pkg/version/internal)"
+  test_ldflags=()
+  # x_defs contains pairs: -X "pkg.Var=value". Iterate in steps of 2.
+  for (( i=0; i<${#x_defs[@]}; i+=2 )); do
+    xflag="${x_defs[i]}"      # -X
+    xval="${x_defs[i+1]}"     # "pkg.Var=value"
+    if [[ "$xval" == *"MainVersion="* ]]; then
+      test_ldflags+=(-X "\"${version_pkg}.MainVersion=${BASE_VERSION}\"")
+    elif [[ "$xval" == *"GitShortSha="* ]]; then
+      # Skip GitShortSha for tests — not needed and changes per commit.
+      :
+    else
+      test_ldflags+=("$xflag" "$xval")
+    fi
+  done
+else
+  # No git tags available — fall back to full ldflags for tests too.
+  test_ldflags=("${x_defs[@]}")
+fi
+
 if [[ "$DEBUG_BUILD" != "yes" ]]; then
-  ldflags+=(-s -w)
+  build_ldflags+=(-s -w)
+  test_ldflags+=(-s -w)
 fi
 
 if [[ "${CGO_ENABLED}" != 0 ]]; then
   echo >&2 "CGO_ENABLED is not 0. Compiling with -linkmode=external"
-  ldflags+=('-linkmode=external')
+  build_ldflags+=('-linkmode=external')
+  test_ldflags+=('-linkmode=external')
 fi
 
 function invoke_go() {
-  tool="$1"
+  local tool="$1"
   shift
+  local flags
+  if [[ "$tool" == "test" ]]; then
+    flags="${test_ldflags[*]}"
+  else
+    flags="${build_ldflags[*]}"
+  fi
   if [[ "$RACE" == "true" ]]; then
-    CGO_ENABLED=1 go "$tool" -race -ldflags="${ldflags[*]}" -tags "$(tr , ' ' <<<"$GOTAGS")" "$@"
+    CGO_ENABLED=1 go "$tool" -race -buildvcs=false -ldflags="${flags}" -tags "$(tr , ' ' <<<"$GOTAGS")" "$@"
   else
-    go "$tool" -ldflags="${ldflags[*]}" -tags "$(tr , ' ' <<<"$GOTAGS")" "$@"
+    go "$tool" -buildvcs=false -ldflags="${flags}" -tags "$(tr , ' ' <<<"$GOTAGS")" "$@"
   fi
 }
 
diff --git a/status.sh b/status.sh
index cb93f0946c8e0..d6f726fd9bdb6 100755
--- a/status.sh
+++ b/status.sh
@@ -1,8 +1,19 @@
 #!/bin/sh
 
-# Note: This requires .git directory in the build context (e.g. builder container)
-echo "STABLE_MAIN_VERSION $(make --quiet --no-print-directory tag)"
-echo "STABLE_COLLECTOR_VERSION $(make --quiet --no-print-directory collector-tag)"
-echo "STABLE_FACT_VERSION $(make --quiet --no-print-directory fact-tag)"
-echo "STABLE_SCANNER_VERSION $(make --quiet --no-print-directory scanner-tag)"
-echo "STABLE_GIT_SHORT_SHA $(make --quiet --no-print-directory shortcommit)"
+# Outputs version variables for go-tool.sh's XDef ldflags injection.
+# Uses direct git/cat commands instead of 'make' to avoid ~15s of
+# Makefile parsing overhead per invocation (5 make calls × ~3s each).
+
+REPO_ROOT="$(cd "$(dirname "$0")" && pwd)"
+
+main_version="${BUILD_TAG:-$(git describe --tags --abbrev=10 --dirty --long --exclude '*-nightly-*' 2>/dev/null || cat "${REPO_ROOT}/VERSION" 2>/dev/null || echo '0.0.0')}"
+collector_version="$(cat "${REPO_ROOT}/COLLECTOR_VERSION" 2>/dev/null || echo '0.0.0')"
+fact_version="$(cat "${REPO_ROOT}/FACT_VERSION" 2>/dev/null || echo '0.0.0')"
+scanner_version="$(cat "${REPO_ROOT}/SCANNER_VERSION" 2>/dev/null || echo '0.0.0')"
+git_short_sha="${SHORTCOMMIT:-$(git rev-parse --short HEAD 2>/dev/null || echo 'unknown')}"
+
+echo "STABLE_MAIN_VERSION ${main_version}"
+echo "STABLE_COLLECTOR_VERSION ${collector_version}"
+echo "STABLE_FACT_VERSION ${fact_version}"
+echo "STABLE_SCANNER_VERSION ${scanner_version}"
+echo "STABLE_GIT_SHORT_SHA ${git_short_sha}"