[Update install instruction for macOS] Update install instruction for macOS

[Minsoo Choo]

---
 doc/install.texi | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/doc/install.texi b/doc/install.texi
index dfe75e34..5a6c8a0b 100644
--- a/doc/install.texi
+++ b/doc/install.texi
@@ -112,6 +112,9 @@ targets like @samp{make install} and @samp{make uninstall} 
work
 correctly.  This target is generally not run by end users.
 @end enumerate
 
+On macOS, users should not use the default perl, but manually install
+it from https://www.perl.org/get.html.
+
 @node Compilers and Options
 @section Compilers and Options
 

base-commit: 078edd8c0fb36b0245df3c6ebd621225dea9b685
-- 
2.37.1 (Apple Git-137.1)