Build style handles building and installing aerc binary.
Makefile should only install remaining files.
diff --git i/GNUmakefile w/GNUmakefile
index 95556b..a83707 100644
--- i/GNUmakefile
+++ w/GNUmakefile
@@ -196,7 +196,6 @@ $(foreach s,$(wildcard stylesets/*),\
 $(foreach t,$(wildcard templates/*),\
 	$(eval $(call install_file,$t,644,$(DESTDIR)$(SHAREDIR)/templates)))
 $(eval $(call install_file,contrib/aerc.desktop,644,$(DESTDIR)$(PREFIX)/share/applications))
-$(eval $(call install_file,aerc,755,$(DESTDIR)$(BINDIR)))
 $(eval $(call install_file,contrib/carddav-query,755,$(DESTDIR)$(BINDIR)))
 
 $(sort $(dirs)):