diff -rupN glibc-2.31/manual/Makefile glibc-2.31.new/manual/Makefile
--- glibc-2.31/manual/Makefile	2020-02-01 19:52:50.000000000 +0800
+++ glibc-2.31.new/manual/Makefile	2021-11-21 04:06:05.906850265 +0800
@@ -172,6 +172,7 @@ include ../Rules
 install-data subdir_install: install
 # Generated files requiring python: libm-err.texi
 # Generated files requiring perl: summary.texi
+ifeq ($(PERL),never)
 ifneq ($(PERL),no)
 ifneq ($(strip $(MAKEINFO)),:)
 install: $(inst_infodir)/libc.info
@@ -181,6 +182,7 @@ install: $(inst_infodir)/libc.info
 	else : ; fi
 endif
 endif
+endif
 # Catchall implicit rule for other installation targets from the parent.
 install-%: ;