Use PKG_CONFIG_LIBDIR instead of PKG_CONFIG_PATH

Makefile

@@ -44,11 +44,11 @@ all: $(EXE)
 	$(info Build OK)
 
 # Set up target-architecture-specific environment variables:
-# CC, PKG_CONFIG_PATH, GOOS, GOARCH
+# CC, PKG_CONFIG_LIBDIR, GOOS, GOARCH
 $(foreach arch,$(ARCHS),\
 	$(if $(findstring $(3rdparty_NATIVE_ARCH),$(arch)),,\
 		$(eval _build/$(arch)/%: private export CC=$(arch)-gcc))\
-	$(eval _build/$(arch)/%: private export PKG_CONFIG_PATH=$(CURDIR)/_3rdparty/tgt/$(arch)/lib/pkgconfig)\
+	$(eval _build/$(arch)/%: private export PKG_CONFIG_LIBDIR=$(CURDIR)/_3rdparty/tgt/$(arch)/lib/pkgconfig)\
 	$(eval _build/$(arch)/%: private export GOOS=\
 		$(or $(if $(findstring linux,$(arch)),linux),\
 			 $(if $(findstring mingw,$(arch)),windows),\
@@ -65,10 +65,10 @@ $(if $(findstring x86_64-linux,$(3rdparty_NATIVE_ARCH)),\
 	$(eval unit-test: private export CC=x86_64-linux-musl-gcc)\
 	$(eval unit-test: private export GOOS=linux)\
 	$(eval unit-test: private export GOARCH=amd64)\
-	$(eval unit-test: private export PKG_CONFIG_PATH=$(CURDIR)/_3rdparty/tgt/x86_64-linux-musl/lib/pkgconfig)\
+	$(eval unit-test: private export PKG_CONFIG_LIBDIR=$(CURDIR)/_3rdparty/tgt/x86_64-linux-musl/lib/pkgconfig)\
 	,\
 	$(eval unit-test: private export CC=$(firstword $(shell which gcc cc)))\
-	$(eval unit-test: private export PKG_CONFIG_PATH=$(CURDIR)/_3rdparty/tgt/$(3rdparty_NATIVE_ARCH)/lib/pkgconfig))
+	$(eval unit-test: private export PKG_CONFIG_LIBDIR=$(CURDIR)/_3rdparty/tgt/$(3rdparty_NATIVE_ARCH)/lib/pkgconfig))
 
 $(EXE) unit-test: private export CGO_ENABLED=1
 $(EXE) unit-test: private export PATH := $(CURDIR)/_3rdparty/tgt/bin:$(PATH)
@@ -92,7 +92,7 @@ unit-test:
 	$(info [+] Running tests...)
 	$(info [+] test_flags=$(test_flags) test_pathspec=$(test_pathspec))
 	$(info [+] GOROOT=$(GOROOT) GOOS=$(GOOS) GOARCH=$(GOARCH) CC=$(CC))
-	$(info [+] PKG_CONFIG_PATH=$(PKG_CONFIG_PATH))
+	$(info [+] PKG_CONFIG_LIBDIR=$(PKG_CONFIG_LIBDIR))
 	$(GOROOT)/bin/go test $(test_flags) \
 		-ldflags '-w -s -linkmode=external -extldflags "$(extldflags)"' \
 		-tags yara_static \
@@ -106,7 +106,7 @@ $(EXE): VERSIONDEF := $(if $(VERSIONSUFFIX),-X $(NAMESPACE).Version=$(VERSION)$(
 $(EXE):
 	$(info [+] Building spyre...)
 	$(info [+] GOROOT=$(GOROOT) GOOS=$(GOOS) GOARCH=$(GOARCH) CC=$(CC))
-	$(info [+] PKG_CONFIG_PATH=$(PKG_CONFIG_PATH))
+	$(info [+] PKG_CONFIG_LIBDIR=$(PKG_CONFIG_LIBDIR))
 	mkdir -p $(@D)
 	$(GOROOT)/bin/go build \
 		-ldflags '$(VERSIONDEF) -w -s -linkmode=external -extldflags "$(extldflags)"' \