+if test "${WithGhc}" != ""
+then
+ bootstrap_host=`"${WithGhc}" +RTS --info | grep '^ ,("Host platform"' | sed -e 's/.*, "//' -e 's/")//' | tr -d '\r'`
+ bootstrap_target=`"${WithGhc}" +RTS --info | grep '^ ,("Target platform"' | sed -e 's/.*, "//' -e 's/")//' | tr -d '\r'`
+ if test "$bootstrap_host" != "$bootstrap_target"
+ then
+ echo "Bootstrapping GHC is a cross compiler. This probably isn't going to work"
+ fi
+fi
+
+# We have to run these unconditionally, but we may discard their
+# results in the following code
+AC_CANONICAL_BUILD
+AC_CANONICAL_HOST
+AC_CANONICAL_TARGET
+
+# If no argument was given for a configuration variable, then discard
+# the guessed canonical system and use the configuration of the
+# bootstrapping ghc. If an argument was given, map it from gnu format
+# to ghc format.
+#
+# For why we do it this way, see: #3637, #1717, #2951
+
+if test "$build_alias" = ""