Revert "Merge pull request #11804 from obsidiansystems/remove-old-make"

This reverts commit 619eeb658a, reversing
changes made to 1af94bf471.

src/libmain/local.mk

@@ -0,0 +1,22 @@
+libraries += libmain
+
+libmain_NAME = libnixmain
+
+libmain_DIR := $(d)
+
+libmain_SOURCES := $(wildcard $(d)/*.cc)
+ifdef HOST_UNIX
+  libmain_SOURCES += $(wildcard $(d)/unix/*.cc)
+endif
+
+INCLUDE_libmain := -I $(d)
+
+libmain_CXXFLAGS += $(INCLUDE_libutil) $(INCLUDE_libstore) $(INCLUDE_libmain)
+
+libmain_LDFLAGS += $(OPENSSL_LIBS)
+
+libmain_LIBS = libstore libutil
+
+libmain_ALLOW_UNDEFINED = 1
+
+$(eval $(call install-file-in, $(buildprefix)$(d)/nix-main.pc, $(libdir)/pkgconfig, 0644))

src/libmain/nix-main.pc.in

@@ -0,0 +1,9 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Nix
+Description: Nix Package Manager
+Version: @PACKAGE_VERSION@
+Libs: -L${libdir} -lnixmain
+Cflags: -I${includedir}/nix -std=c++2a