--- Makefile.orig	2017-12-17 14:07:55 UTC
+++ Makefile
@@ -87,7 +87,8 @@ else
 endif
 
 prefix ?= /usr/local
-destdir ?= $(prefix)/lib/pony/$(tag)
+destdir ?=
+libdir ?= lib/pony/$(tag)
 
 LIB_EXT ?= a
 BUILD_FLAGS = -march=$(arch) -mtune=$(tune) -Werror -Wconversion \
@@ -244,10 +245,10 @@ ifndef LLVM_CONFIG
     LLVM_CONFIG = llvm-config
     LLVM_LINK = llvm-link
     LLVM_OPT = opt
-  else ifneq (,$(shell which llvm-config-5.0 2> /dev/null))
-    LLVM_CONFIG = llvm-config-5.0
-    LLVM_LINK = llvm-link-5.0
-    LLVM_OPT = opt-5.0
+  else ifneq (,$(shell which llvm-config50 2> /dev/null))
+    LLVM_CONFIG = llvm-config50
+    LLVM_LINK = llvm-link50
+    LLVM_OPT = opt50
   else ifneq (,$(shell which llvm-config-4.0 2> /dev/null))
     LLVM_CONFIG = llvm-config-4.0
     LLVM_LINK = llvm-link-4.0
@@ -775,44 +776,44 @@ install: libponyc libponyrt libponyrt-pi
 else
 install: libponyc libponyrt ponyc
 endif
-	@mkdir -p $(destdir)/bin
-	@mkdir -p $(destdir)/docs-support
-	@mkdir -p $(destdir)/lib
-	@mkdir -p $(destdir)/include/pony/detail
-	$(SILENT)cp $(PONY_BUILD_DIR)/libponyrt.a $(destdir)/lib
+	@mkdir -p $(destdir)/$(prefix)/$(libdir)/bin
+	@mkdir -p $(destdir)/$(prefix)/$(libdir)/docs-support
+	@mkdir -p $(destdir)/$(prefix)/$(libdir)/lib
+	@mkdir -p $(destdir)/$(prefix)/$(libdir)/include/pony/detail
+	$(SILENT)cp $(PONY_BUILD_DIR)/libponyrt.a $(destdir)/$(prefix)/$(libdir)/lib
 ifeq ($(OSTYPE),linux)
-	$(SILENT)cp $(PONY_BUILD_DIR)/libponyrt-pic.a $(destdir)/lib
+	$(SILENT)cp $(PONY_BUILD_DIR)/libponyrt-pic.a $(destdir)/$(prefix)/$(libdir)/lib
 endif
 ifneq ($(wildcard $(PONY_BUILD_DIR)/libponyrt.bc),)
-	$(SILENT)cp $(PONY_BUILD_DIR)/libponyrt.bc $(destdir)/lib
+	$(SILENT)cp $(PONY_BUILD_DIR)/libponyrt.bc $(destdir)/$(prefix)/$(libdir)/lib
 endif
 ifneq ($(wildcard $(PONY_BUILD_DIR)/libdtrace_probes.a),)
-	$(SILENT)cp $(PONY_BUILD_DIR)/libdtrace_probes.a $(destdir)/lib
+	$(SILENT)cp $(PONY_BUILD_DIR)/libdtrace_probes.a $(destdir)/$(prefix)/$(libdir)/lib
 endif
-	$(SILENT)cp $(PONY_BUILD_DIR)/libponyc.a $(destdir)/lib
-	$(SILENT)cp $(PONY_BUILD_DIR)/ponyc $(destdir)/bin
-	$(SILENT)cp src/libponyrt/pony.h $(destdir)/include
-	$(SILENT)cp src/common/pony/detail/atomics.h $(destdir)/include/pony/detail
-	$(SILENT)cp -r packages $(destdir)/
-	$(SILENT)cp -r .docs/* $(destdir)/docs-support/
+	$(SILENT)cp $(PONY_BUILD_DIR)/libponyc.a $(destdir)/$(prefix)/$(libdir)/lib
+	$(SILENT)cp $(PONY_BUILD_DIR)/ponyc $(destdir)/$(prefix)/$(libdir)/bin
+	$(SILENT)cp src/libponyrt/pony.h $(destdir)/$(prefix)/$(libdir)/include
+	$(SILENT)cp src/common/pony/detail/atomics.h $(destdir)/$(prefix)/$(libdir)/include/pony/detail
+	$(SILENT)cp -r packages $(destdir)/$(prefix)/$(libdir)/
+	$(SILENT)cp -r .docs/* $(destdir)/$(prefix)/$(libdir)/docs-support/
 ifeq ($$(symlink),yes)
-	@mkdir -p $(prefix)/bin
-	@mkdir -p $(prefix)/lib
-	@mkdir -p $(prefix)/include/pony/detail
-	$(SILENT)ln $(symlink.flags) $(destdir)/bin/ponyc $(prefix)/bin/ponyc
-	$(SILENT)ln $(symlink.flags) $(destdir)/lib/libponyrt.a $(prefix)/lib/libponyrt.a
+	@mkdir -p $(destdir)/$(prefix)/bin
+	@mkdir -p $(destdir)/$(prefix)/lib
+	@mkdir -p $(destdir)/$(prefix)/include/pony/detail
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/bin/ponyc $(destdir)/$(prefix)/bin/ponyc
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/lib/libponyrt.a $(destdir)/$(prefix)/lib/libponyrt.a
 ifeq ($(OSTYPE),linux)
-	$(SILENT)ln $(symlink.flags) $(destdir)/lib/libponyrt-pic.a $(prefix)/lib/libponyrt-pic.a
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/lib/libponyrt-pic.a $(destdir)/$(prefix)/lib/libponyrt-pic.a
 endif
 ifneq ($(wildcard $(destdir)/lib/libponyrt.bc),)
-	$(SILENT)ln $(symlink.flags) $(destdir)/lib/libponyrt.bc $(prefix)/lib/libponyrt.bc
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/lib/libponyrt.bc $(destdir)/$(prefix)/lib/libponyrt.bc
 endif
 ifneq ($(wildcard $(PONY_BUILD_DIR)/libdtrace_probes.a),)
-	$(SILENT)ln $(symlink.flags) $(destdir)/lib/libdtrace_probes.a $(prefix)/lib/libdtrace_probes.a
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/lib/libdtrace_probes.a $(destdir)/$(prefix)/lib/libdtrace_probes.a
 endif
-	$(SILENT)ln $(symlink.flags) $(destdir)/lib/libponyc.a $(prefix)/lib/libponyc.a
-	$(SILENT)ln $(symlink.flags) $(destdir)/include/pony.h $(prefix)/include/pony.h
-	$(SILENT)ln $(symlink.flags) $(destdir)/include/pony/detail/atomics.h $(prefix)/include/pony/detail/atomics.h
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/lib/libponyc.a $(destdir)/$(prefix)/lib/libponyc.a
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/include/pony.h $(destdir)/$(prefix)/include/pony.h
+	$(SILENT)ln $(symlink.flags) ../$(libdir)/include/pony/detail/atomics.h $(destdir)/$(prefix)/include/pony/detail/atomics.h
 endif
 endef
 
