diff -uNr boinc/client/Makefile.am boinc.mod/client/Makefile.am
--- boinc/client/Makefile.am	2022-07-18 18:32:21.000000000 +0800
+++ boinc.mod/client/Makefile.am	2022-09-11 21:07:05.043844110 +0800
@@ -25,7 +25,7 @@
 endif
 
 bin_PROGRAMS = boinc_client boinccmd boinc
-if !OS_WIN32
+if OS_DARWIN
 bin_PROGRAMS += switcher
 endif
 
@@ -139,12 +139,12 @@
 
 boinc$(EXEEXT): boinc_client$(EXEEXT)
 	rm -f boinc$(EXEEXT) .libs/boinc$(EXEEXT)
-	$(LN) boinc_client$(EXEEXT) boinc$(EXEEXT)
-	if test -f .libs/boinc_client$(EXEEXT) ; then $(LN) .libs/boinc_client$(EXEEXT) .libs/boinc$(EXEEXT) ; fi
+	$(LN) -sfr boinc_client$(EXEEXT) boinc$(EXEEXT)
+	if test -f .libs/boinc_client$(EXEEXT) ; then $(LN) -sfr .libs/boinc_client$(EXEEXT) .libs/boinc$(EXEEXT) ; fi
 
 install-exec-hook:
 	rm -f $(DESTDIR)$(exec_prefix)/bin/boinc$(EXEEXT)
-	$(LN) $(DESTDIR)$(exec_prefix)/bin/boinc_client$(EXEEXT) $(DESTDIR)$(exec_prefix)/bin/boinc$(EXEEXT)
+	$(LN) -sfr $(DESTDIR)$(exec_prefix)/bin/boinc_client$(EXEEXT) $(DESTDIR)$(exec_prefix)/bin/boinc$(EXEEXT)
 
 ## these source files need to be specified because no rule uses them.