The version of src/player/player-damage.c currently in the develop branch calls get_rnd_line() but does not have a prototype for that function. With the default compiler options on clang (at least for version 12), that triggers a compiler error.
I should have specified that the error occurred when reporting the score had been disabled (WORLD_SCORE not set so io/report.h does not include io/files-util.h).
The version of src/player/player-damage.c currently in the develop branch calls get_rnd_line() but does not have a prototype for that function. With the default compiler options on clang (at least for version 12), that triggers a compiler error.
This commit, https://osdn.net/projects/hengbandforosx/scm/git/hengbandosx/commits/9e8a2452f24e526c7d51798c480352a07f68707f , (clang-player-damage-missing-prototype branch on the hengbandforosx project; the branch is based off Hengband's develop branch) pulls in io/files-util.h to get the prototype for get_rnd_line().