Shell hack to find TLC in a hard-coded list of directories.

Makefile.config

-TLC := ~/tmp/tlc/src
+# This is a crude way of discovering where TLC is installed.
+# We pick the first directory that exists in the following hard-coded list.
+TLC_CANDIDATES := ~/dev/tlc/src
+ifndef TLC
+  TLC := $(shell for d in $(TLC_CANDIDATES) ; do \
+                   if [ -d $$d ] ; then echo $$d && exit 0 ; fi ; \
+                 done)
+endif
+ifndef TLC
+  $(error Unable to find TLC. See Makefile.config)
+endif