GNUmakefile: fix build failure without libseinux

.github/workflows/CICD.yml

@@ -273,10 +273,7 @@ jobs:
         target: aarch64-unknown-linux-gnu
     - uses: taiki-e/install-action@nextest
     - uses: Swatinem/rust-cache@v2
-    - name: Install/setup prerequisites
-      shell: bash
-      run: |
-        sudo apt-get -y update ; sudo apt-get -y install libselinux1-dev
+    # Test build on the system missing libselinux (don't install libselinux1-dev at here)
     - name: Run sccache-cache
       uses: mozilla-actions/sccache-action@v0.0.9
     - name: "`make build`"

.github/workflows/GnuTests.yml

@@ -78,9 +78,9 @@ jobs:
     - name: Install dependencies
       shell: bash
       run: |
-        ## Install dependencies
+        ## Install dependencies (without libselinux)
         sudo apt-get update
-        sudo apt-get install -y autopoint gperf gdb python3-pyinotify valgrind libexpect-perl libacl1-dev libattr1-dev libcap-dev libselinux1-dev attr quilt
+        sudo apt-get install -y autopoint gperf gdb python3-pyinotify valgrind libexpect-perl libacl1-dev libattr1-dev libcap-dev attr quilt
     - name: Add various locales
       shell: bash
       run: |

GNUmakefile

@@ -195,15 +195,11 @@ HASHSUM_PROGS := \
 
 $(info Detected OS = $(OS))
 
-# Build the SELinux programs only on Linux
-ifeq ($(filter $(OS),Linux),)
-	SELINUX_PROGS :=
-endif
-
 ifneq ($(OS),Windows_NT)
-	PROGS := $(PROGS) $(UNIX_PROGS)
-# Build the selinux command even if not on the system
-	PROGS := $(PROGS) $(SELINUX_PROGS)
+	PROGS += $(UNIX_PROGS)
+endif
+ifeq ($(SELINUX_ENABLED),1)
+	PROGS += $(SELINUX_PROGS)
 endif
 
 UTILS ?= $(filter-out $(SKIP_UTILS),$(PROGS))