Install some pkgconfig files

src/libexpr/local.mk

@@ -26,3 +26,5 @@ $(d)/lexer-tab.cc $(d)/lexer-tab.hh: $(d)/lexer.l
 clean-files += $(d)/parser-tab.cc $(d)/parser-tab.hh $(d)/lexer-tab.cc $(d)/lexer-tab.hh
 
 dist-files += $(d)/parser-tab.cc $(d)/parser-tab.hh $(d)/lexer-tab.cc $(d)/lexer-tab.hh
+
+$(eval $(call install-file-in, $(d)/nix-expr.pc, $(libdir)/pkgconfig, 0644))

src/libexpr/nix-expr.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Nix
+Description: Nix Package Manager
+Version: @PACKAGE_VERSION@
+Requires: nix-store bdw-gc
+Libs: -L${libdir} -lnixexpr
+Cflags: -I${includedir}/nix