-# to rebuild only the specifically-requested Lisp files (or skip
-# after-xc.core completely if no Lisp files are specifically
-# requested), then (2) run GENESIS.
+# to rebuild only obviously-out-of-date Lisp files, then (2) run
+# GENESIS.
+sbcl --core output/after-xc.core <<'EOF' || exit 1
+ (load "src/cold/slam.lisp")
+EOF
+# (This ^ used to be
+# for f in $*; do echo "(target-compile-stem \"$f\")"; done \
+# | sbcl --core output/after-xc.core || exit 1
+# and perhaps we do something like this again, allowing explicit
+# rebuild-this-stem requests on the command line to supplement
+# the rebuild-obviously-outdated-stems logic above.)