The Makefile in the article is actually incorrect and only "works" by accident: main.o must have a dependency on mod1.pcm which is one of the outputs produced w

The Makefile in the article is actually incorrect and only "works" by accident: main.o must have a dependency on mod1.pcm which is one of the outputs produced when compiling mod1.ccm and is needed whenever compiling any transaction unit that imports mod1.