doc: install: mention -p may lose some of -C speed benefits

* doc/coreutils.texi (install invocation): Mention that
--preserve-timestamps may lose some of the speed advantages of -C,
due to needing to update timestamps for each build.

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 2fa8896704c92cc923208e9ef34605391707e49b..50afa99fc179b322f9961a0fca70146293980842 100644 (file)
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -9835,7 +9835,9 @@ This option is best used in conjunction with @option{--user},
 incorrectly determines the default attributes that installed files would have
 (as it doesn't consider setgid directories and POSIX default ACLs for example).
 This could result in redundant copies or attributes that are not reset to the
-correct defaults.
+correct defaults.  Note the @option{--preserve-timestamps} option may
+lose some of the speed benefits with repeated builds, as timestamps
+would be updated for each build.
 
 @optItem{install,-c,}
 Ignored; for compatibility with old Unix versions of @command{install}.