This fixes build problems of the form
ghc-cabal: Version mismatch between ghc and ghc-pkg
$(GHC_CABAL_DIR)_dist-dummy-ghc_MODULES = dummy-ghc
$(GHC_CABAL_DIR)_dist-dummy-ghc_PROG = dummy-ghc$(exeext)
$(GHC_CABAL_DIR)_dist-dummy-ghc_MODULES = dummy-ghc
$(GHC_CABAL_DIR)_dist-dummy-ghc_PROG = dummy-ghc$(exeext)
-$(GHC_CABAL_DIR)/dist-dummy-ghc/build/dummy-ghc.hs : $(GHC_CABAL_DIR)/ghc.mk $(MKDIRHIER)
+# depend on config.mk, so we pick up the new version number if it changes.
+$(GHC_CABAL_DIR)/dist-dummy-ghc/build/dummy-ghc.hs : $(GHC_CABAL_DIR)/ghc.mk $(MKDIRHIER) $(TOP)/mk/config.mk
$(MKDIRHIER) $(dir $@)
echo "import System.Environment; import System.Cmd; import System.Exit" >$@
echo "main = do args <- getArgs; if args == [\"--numeric-version\"] then putStrLn \"$(ProjectVersion)\" else do e <- rawSystem \"$(GHC_STAGE0)\" args; exitWith e" >>$@
$(MKDIRHIER) $(dir $@)
echo "import System.Environment; import System.Cmd; import System.Exit" >$@
echo "main = do args <- getArgs; if args == [\"--numeric-version\"] then putStrLn \"$(ProjectVersion)\" else do e <- rawSystem \"$(GHC_STAGE0)\" args; exitWith e" >>$@