Allow system versions of libwhich and libblastrampoline (JuliaLang#43000

)

Make.inc

@@ -1085,6 +1085,12 @@ else
 PATCHELF := $(build_depsbindir)/patchelf
 endif
 
+ifeq ($(USE_SYSTEM_LIBWHICH), 1)
+LIBWHICH := libwhich
+else
+LIBWHICH := $(build_depsbindir)/libwhich
+endif
+
 # On aarch64 and powerpc64le, we assume the page size is 64K. Our binutils linkers
 # and such already assume this, but `patchelf` seems to be behind the times. We
 # explicitly tell it to use this large page size so that when we rewrite rpaths and

base/Makefile

@@ -170,7 +170,7 @@ endif
 
 define symlink_system_library
 libname_$2 := $$(notdir $(call versioned_libname,$2,$3))
-libpath_$2 := $$(shell $$(call spawn,$$(build_depsbindir)/libwhich) -p $$(libname_$2) 2>/dev/null)
+libpath_$2 := $$(shell $$(call spawn,$$(LIBWHICH)) -p $$(libname_$2) 2>/dev/null)
 symlink_$2: $$(build_private_libdir)/$$(libname_$2)
 $$(build_private_libdir)/$$(libname_$2):
  @if [ -e "$$(libpath_$2)" ]; then \

deps/Makefile

@@ -159,9 +159,11 @@ DEP_LIBS += lapack
 endif
 endif
 
+ifeq ($(USE_SYSTEM_LIBWHICH), 0)
 ifneq ($(OS), WINNT)
 DEP_LIBS += libwhich
 endif
+endif
 
 # unlist targets that have not been converted to use the staged-install
 DEP_LIBS_STAGED := $(filter-out suitesparse-wrapper,$(DEP_LIBS))