This line
install_sh_DATA = $(install_sh) -c -m 644
uses the flag -c, however, according to man install the flag doesn't do anything. Should this be -C instead?
-c (ignored)
-C, --compare
compare each pair of source and destination files, and in some cases, do not modify the destination at all
This line
uses the flag
-c, however, according toman installthe flag doesn't do anything. Should this be-Cinstead?