a lot of work on the util/configure script.

t/sanity.t

@@ -0,0 +1,40 @@
+use strict;
+use warnings;
+
+use Test::More tests => 1;
+use Test::Differences;
+
+sub shell (@);
+sub cd ($);
+
+my $ver = `bash util/ver`;
+chomp $ver;
+
+shell "make";
+
+cd "ngx_openresty-$ver";
+shell "./configure --help > help.txt";
+
+open my $in, "help.txt" or
+    die "Cannot open help.txt for reading: $!\n";
+my $got = do { local $/; <$in> };
+close $in;
+
+open $in, "../t/help.txt" or
+    die "Cannot open ../t/help.txt for reading: $!\n";
+my $expected = do { local $/; <$in> };
+close $in;
+
+eq_or_diff $got, $expected, "--help ok";
+
+sub shell (@) {
+    print "@_\n";
+    system(@_) == 0 or die "failed to run command @_\n";
+}
+
+sub cd ($) {
+    my $dir = shift;
+    print("cd $dir\n");
+    chdir $dir or die "failed to cd $dir: $!\n";
+}
+