Philip, I've tried to merge you latest PR but I have a problem with
module compiled with -fsanitize-address. This compiles the module with
ASan aka AddressSanitizer on GCC. You've enable it to debug memory
problems I guess and it looks useful but I cannot load them.

[*] ./modt-error: running make
gcc -fsanitize=address -ggdb3 -Wall -I../../src -fPIC -c modt-error.c
gcc -shared -fsanitize=address -o modt-error.so modt-error.o
../../lib-src/make-docfile modt-error.c > modt-error.doc
rm modt-error.o
[*] ./modt-error: running test
../src/emacs -batch -L . -l ert -l ./modt-error/test.el -f
ert-run-tests-batch-and-exit
==24402==ASan runtime does not come first in initial library list; you
should either link runtime to your application or manually preload it
with LD_PRELOAD.
[E] ./modt-error: test failed

I'm sure I'm missing something obvious...