-_am_tools=${am_cv_prog_tar_ustar-$_am_tools}
-# Do not fold the above two line into one, because Tru64 sh and
-# Solaris sh will not grok spaces in the rhs of '-'.
-for _am_tool in $_am_tools
-do
- case $_am_tool in
- gnutar)
- for _am_tar in tar gnutar gtar;
- do
- { echo "$as_me:$LINENO: $_am_tar --version" >&5
+
+# The POSIX 1988 'ustar' format is defined with fixed-size fields.
+ # There is notably a 21 bits limit for the UID and the GID. In fact,
+ # the 'pax' utility can hang on bigger UID/GID (see automake bug#8343
+ # and bug#13588).
+ am_max_uid=2097151 # 2^21 - 1
+ am_max_gid=$am_max_uid
+ # The $UID and $GID variables are not portable, so we need to resort
+ # to the POSIX-mandated id(1) utility. Errors in the 'id' calls
+ # below are definitely unexpected, so allow the users to see them
+ # (that is, avoid stderr redirection).
+ am_uid=`id -u || echo unknown`
+ am_gid=`id -g || echo unknown`
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether UID '$am_uid' is supported by ustar format" >&5
+$as_echo_n "checking whether UID '$am_uid' is supported by ustar format... " >&6; }
+ if test $am_uid -le $am_max_uid; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+ else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+ _am_tools=none
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether GID '$am_gid' is supported by ustar format" >&5
+$as_echo_n "checking whether GID '$am_gid' is supported by ustar format... " >&6; }
+ if test $am_gid -le $am_max_gid; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+ else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+ _am_tools=none
+ fi
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking how to create a ustar tar archive" >&5
+$as_echo_n "checking how to create a ustar tar archive... " >&6; }
+
+ # Go ahead even if we have the value already cached. We do so because we
+ # need to set the values for the 'am__tar' and 'am__untar' variables.
+ _am_tools=${am_cv_prog_tar_ustar-$_am_tools}
+
+ for _am_tool in $_am_tools; do
+ case $_am_tool in
+ gnutar)
+ for _am_tar in tar gnutar gtar; do
+ { echo "$as_me:$LINENO: $_am_tar --version" >&5