MT#55283 Abort make if required package is not found

Closes #2027

Change-Id: I609d326fe69c82268f4e58411549cf26afc68409

lib/deps.Makefile

@@ -1,12 +1,15 @@
 # Define build flags for used dependencies.
 
-$(top_srcdir)/config.mk:
-	$(top_srcdir)/utils/gen-common-flags >$@
+$(top_srcdir)/config.mk: $(top_srcdir)/utils/gen-common-flags \
+		$(top_srcdir)/utils/gen-bcg729-flags \
+		$(top_srcdir)/utils/gen-codec-chain-flags
+	$(top_srcdir)/utils/gen-common-flags >$@.new
 ifeq (,$(filter pkg.ngcp-rtpengine.nobcg729,${DEB_BUILD_PROFILES}))
-	$(top_srcdir)/utils/gen-bcg729-flags >>$@
+	$(top_srcdir)/utils/gen-bcg729-flags >>$@.new
 endif
 ifneq (,$(filter pkg.ngcp-rtpengine.codec-chain,${DEB_BUILD_PROFILES}))
-	$(top_srcdir)/utils/gen-codec-chain-flags >>$@
+	$(top_srcdir)/utils/gen-codec-chain-flags >>$@.new
 endif
+	mv $@.new $@
 
 include $(top_srcdir)/config.mk

utils/gen-common-flags

@@ -5,6 +5,11 @@ gen-pkgconf-flags()
   local var="$1"
   local pc="$2"
 
+  if ! pkg-config --exists "${pc}"; then
+    echo "Error: Required package '${pc}' not found" >&2
+    exit 1
+  fi
+
   echo "export CFLAGS_${var} LDLIBS_${var}"
   echo "CFLAGS_${var} := $(pkg-config --cflags "${pc}")"
   echo "LDLIBS_${var} := $(pkg-config --libs "${pc}")"