doc: Mention the effects of AC_SYS_LARGEFILE.

[gnulib.git] / doc / posix-functions / truncate.texi

diff --git a/doc/posix-functions/truncate.texi b/doc/posix-functions/truncate.texi
index eb10406..55e7f1a 100644 (file)
--- a/doc/posix-functions/truncate.texi
+++ b/doc/posix-functions/truncate.texi
@@ -15,4 +15,8 @@ Portability problems not fixed by Gnulib:
 @item
 This function is missing on some platforms:
 mingw.
+@item
+On platforms where @code{off_t} is a 32-bit type, this function is not
+applicable to arbitrary lengths for files larger than 2 GB.  The fix is to
+use the @code{AC_SYS_LARGEFILE} macro.
 @end itemize