Posix 2008 requires make to set errexit.

[Ralf Wildenhues]

A small comment update, for maint.  This is documented in autoconf.texi
'Failure in Make Rules'.

Cheers,
Ralf

    Posix 2008 requires make to set errexit.
    
    * lib/am/check.am: Update comment.

diff --git a/lib/am/check.am b/lib/am/check.am
index e519391..c612b22 100644
--- a/lib/am/check.am
+++ b/lib/am/check.am
@@ -87,7 +87,7 @@ am__text_box = $(AWK) '{                              \
 }'
 
 # Solaris 10 'make', and several other traditional 'make' implementations,
-# pass "-e" to $(SHELL).  This contradicts POSIX.  Work around the problem
+# pass "-e" to $(SHELL), and POSIX 2008 even requires this.  Work around it
 # by disabling -e (using the XSI extension "set +e") if it's set.
 am__sh_e_setup = case $$- in *e*) set +e;; esac