--- autoconf-2.70/tests/local.at.orig	2021-01-07 20:29:32.906519857 +0100
+++ autoconf-2.70/tests/local.at	2021-01-07 20:51:45.695966183 +0100
@@ -351,7 +351,7 @@
 #   Set by AC_OUTPUT.
 # - AC_SUBST'ed variables
 #   (FIXME: Generate a list of these automatically.)
-# - _|@|.[*#?$].|argv|ARGC|LINENO|OLDPWD|PIPESTATUS|RANDOM|SECONDS
+# - _|@|.[*#?$].|argv|ARGC|LINENO|OLDPWD|PIPESTATUS|RANDOM|SECONDS|BASHPID|EPOCHREALTIME|KSH_MATCH
 #   |START_TIME|ToD|_AST_FEATURES
 #   Some variables some shells use and change.
 #   `.[*#?$].' catches `$#' etc. which are displayed like this:
@@ -402,7 +402,7 @@
       [AWK|LEX|LEXLIB|LEX_OUTPUT_ROOT|LN_S|M4|MKDIR_P|RANLIB|SET_MAKE|YACC],
       [GREP|[EF]GREP|SED],
       [[_@]|.[*@%:@?$].],
-      [argv|ARGC|LINENO|BASH_ARGC|BASH_ARGV|OLDPWD|PIPESTATUS|RANDOM],
+      [argv|ARGC|LINENO|BASH_ARGC|BASH_ARGV|OLDPWD|PIPESTATUS|RANDOM|BASHPID|EPOCHREALTIME|KSH_MATCH],
       [SECONDS|START_TIME|ToD|_AST_FEATURES]))=' \
      $act_file ||
        test $? -eq 1 || echo failed >&2
@@ -432,7 +432,7 @@
 # - Variables with unstable values in at least some shells:
 #   - OLDPWD [bash, zsh]
 #   - PPID [bash, zsh]
-#   - RANDOM [bash, zsh]
+#   - RANDOM [bash, zsh, mksh]
 #   - SECONDS [bash, zsh]
 #   - START_TIME [NetBSD sh]
 #   - ToD [NetBSD sh]
@@ -443,6 +443,9 @@
 #   - BASH_ARGV [bash]
 #   - LINENO [Posix]
 #   - _AST_FEATURES [ksh93]
+#   - BASHPID [bash, mksh]
+#   - EPOCHREALTIME [zsh, mksh]
+#   - KSH_MATCH [mksh]
 # - Optionally, variables that are expected to vary in a particular test.
 #   This is controlled by the EXTRA-VARIANCE argument, which is a
 #   whitespace-separated sequence of tokens.  Each token means to ignore
@@ -481,6 +484,9 @@
 	/^PPID=/ d
 	/^RANDOM=/ d
 	/^SECONDS=/ d
+	/^BASHPID=/ d
+	/^EPOCHREALTIME=/ d
+	/^KSH_MATCH=/ d
 	/^START_TIME=/ d
 	/^ToD=/ d
 	/'\'\\\$\''=/ d