diff --git a/mk/target.mk b/mk/target.mk
index 5694c907950..67bb055dfc7 100644
--- a/mk/target.mk
+++ b/mk/target.mk
@@ -14,13 +14,6 @@
 # $(2) is the target triple
 # $(3) is the host triple
 
-# If you are making non-backwards compatible changes to the runtime
-# (resp.  corelib), set this flag to 1.  It will cause stage1 to use
-# the snapshot runtime (resp. corelib) rather than the runtime
-# (resp. corelib) from the working directory.
-USE_SNAPSHOT_RUNTIME=0
-USE_SNAPSHOT_CORELIB=0
-USE_SNAPSHOT_STDLIB=0
 
 define TARGET_STAGE_N
 
@@ -59,86 +52,17 @@ $$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_LIBSYNTAX): \
 	@$$(call E, compile_and_link: $$@)
 	$$(STAGE$(1)_T_$(2)_H_$(3)) $(BORROWCK) -o $$@ $$< && touch $$@
 
-endef
-
-# The stage0 (snapshot) compiler produces binaries that expect the
-# snapshot runtime.  Normally the working directory runtime and
-# snapshot runtime are compatible, so this is no problem. But
-# sometimes we want to make non-backwards-compatible changes.  In
-# those cases, the stage1 compiler and libraries (which are produced
-# by stage0) should use the runtime from the snapshot.  The stage2
-# compiler and libraries (which are produced by stage1) will be the
-# first that are expecting to run against the runtime as defined in
-# the working directory.
-#
-# The catch is that you may not add new functions to the runtime
-# in this case!
-#
-# Arguments are the same as for TARGET_BASE_STAGE_N
-define TARGET_RT_FROM_SNAPSHOT
-
-$$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_RUNTIME): \
-		$$(HLIB$(1)_H_$(3))/$$(CFG_RUNTIME)
-	@$$(call E, cp: $$@)
-	$$(Q)cp $$< $$@
-
-endef
-
-# This rule copies from the runtime for the working directory.  It
-# applies to targets produced by stage1 or later.  See comment on
-# previous rule.
-#
-# Arguments are the same as for TARGET_BASE_STAGE_N
-define TARGET_RT_FROM_WD
-
 $$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_RUNTIME): \
 		rt/$(2)/$$(CFG_RUNTIME)
 	@$$(call E, cp: $$@)
 	$$(Q)cp $$< $$@
 
-endef
-
-# As above, but builds the corelib either by taking it out of the
-# snapshot or from the working directory.
-
-define TARGET_CORELIB_FROM_SNAPSHOT
-
-$$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_CORELIB): \
-		$$(HLIB$(1)_H_$(3))/$$(CFG_CORELIB) \
-		$$(CORELIB_INPUTS) \
-		$$(TSREQ$(1)_T_$(2)_H_$(3))
-	@$$(call E, cp: $$@)
-	$$(Q)cp $$< $$@
-	$$(Q)cp $$(HLIB$(1)_H_$(3))/$$(CORELIB_GLOB) \
-		$$(TLIB$(1)_T_$(2)_H_$(3))
-
-endef
-
-define TARGET_CORELIB_FROM_WD
-
 $$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_CORELIB): \
 		$$(CORELIB_CRATE) $$(CORELIB_INPUTS) \
 		$$(TSREQ$(1)_T_$(2)_H_$(3))
 	@$$(call E, compile_and_link: $$@)
 	$$(STAGE$(1)_T_$(2)_H_$(3)) -o $$@ $$< && touch $$@
 
-endef
-
-define TARGET_STDLIB_FROM_SNAPSHOT
-
-$$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_STDLIB): \
-		$$(HLIB$(1)_H_$(3))/$$(CFG_STDLIB) \
-		$$(STDLIB_INPUTS) \
-		$$(TSREQ$(1)_T_$(2)_H_$(3))
-	@$$(call E, cp: $$@)
-	$$(Q)cp $$< $$@
-	$$(Q)cp $$(HLIB$(1)_H_$(3))/$$(STDLIB_GLOB) \
-		$$(TLIB$(1)_T_$(2)_H_$(3))
-
-endef
-
-define TARGET_STDLIB_FROM_WD
-
 $$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_STDLIB): \
 		$$(STDLIB_CRATE) $$(STDLIB_INPUTS) \
 	        $$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_CORELIB) \
@@ -155,52 +79,3 @@ $(foreach source,$(CFG_TARGET_TRIPLES),				\
   $(eval $(call TARGET_STAGE_N,1,$(target),$(source)))		\
   $(eval $(call TARGET_STAGE_N,2,$(target),$(source)))		\
   $(eval $(call TARGET_STAGE_N,3,$(target),$(source)))))
-
-# Host triple either uses the snapshot runtime or runtime from
-# working directory, depending on the USE_SNAPSHOT_RUNTIME var.
-ifeq ($(USE_SNAPSHOT_RUNTIME),1)
-    $(foreach src,$(CFG_HOST_TRIPLE),\
-		$(eval $(call TARGET_RT_FROM_SNAPSHOT,0,$(src),$(src))))
-else 
-    $(foreach src,$(CFG_HOST_TRIPLE),\
-		$(eval $(call TARGET_RT_FROM_WD,0,$(src),$(src))))
-endif
-
-ifeq ($(USE_SNAPSHOT_CORELIB),1)
-    $(foreach src,$(CFG_HOST_TRIPLE),\
-		$(eval $(call TARGET_CORELIB_FROM_SNAPSHOT,0,$(src),$(src))))
-else 
-    $(foreach src,$(CFG_HOST_TRIPLE),\
-		$(eval $(call TARGET_CORELIB_FROM_WD,0,$(src),$(src))))
-endif
-
-ifeq ($(USE_SNAPSHOT_STDLIB),1)
-    $(foreach src,$(CFG_HOST_TRIPLE),\
-		$(eval $(call TARGET_STDLIB_FROM_SNAPSHOT,0,$(src),$(src))))
-else
-    $(foreach src,$(CFG_HOST_TRIPLE),\
-		$(eval $(call TARGET_STDLIB_FROM_WD,0,$(src),$(src))))
-endif
-
-# Non-host triples build the stage0 runtime from the working directory
-$(foreach source,$(CFG_TARGET_TRIPLES),				\
- $(foreach target,$(NON_HOST_TRIPLES),				\
-  $(eval $(call TARGET_RT_FROM_WD,0,$(target),$(source)))       \
-  $(eval $(call TARGET_CORELIB_FROM_WD,0,$(target),$(source)))  \
-  $(eval $(call TARGET_STDLIB_FROM_WD,0,$(target),$(source)))  \
-))
-
-# After stage0, always build the stage0 runtime from the working directory
-$(foreach source,$(CFG_TARGET_TRIPLES),				\
- $(foreach target,$(CFG_TARGET_TRIPLES),			\
-  $(eval $(call TARGET_RT_FROM_WD,1,$(target),$(source)))	\
-  $(eval $(call TARGET_RT_FROM_WD,2,$(target),$(source)))	\
-  $(eval $(call TARGET_RT_FROM_WD,3,$(target),$(source)))  	\
-  $(eval $(call TARGET_CORELIB_FROM_WD,1,$(target),$(source)))	\
-  $(eval $(call TARGET_CORELIB_FROM_WD,2,$(target),$(source)))	\
-  $(eval $(call TARGET_CORELIB_FROM_WD,3,$(target),$(source)))	\
-  $(eval $(call TARGET_STDLIB_FROM_WD,1,$(target),$(source)))	\
-  $(eval $(call TARGET_STDLIB_FROM_WD,2,$(target),$(source)))	\
-  $(eval $(call TARGET_STDLIB_FROM_WD,3,$(target),$(source)))	\
-))
-