Makefile incompatibility
Earlier today I tried to compile Frotz both under CygWin and under Linux running in Windows 10, and both of these complained about line 300 in the Makefile. Unfortunately I don't have the exact error message, because I can't reproduce it on my main system, but it's this line:
@echo "Not in a git repository or git command not found. Cannot make a tarball."
The line is indented with spaces. Changing it to a TAB instead fixed the error.
(For CygWin I also had to uncomment "NO_STRDUP", but other than that both seemed to work fine after that change.)