have ask_tree be more specific in its error reporting.

make sure the child has the same effective and real ids,
as perl interprets it as "setuid, refuse to debug"
go to the end of the pipe so the child doesn't exit
prematurely (didn't use to happen but now it does)

help from afresh1@ in diagnosing that one.

1 files changed, 15 insertions, 6 deletions

diff --git a/usr.sbin/pkg_add/OpenBSD/PkgCreate.pm b/usr.sbin/pkg_add/OpenBSD/PkgCreate.pm
index 1feddbc76a0..40c2f106f0f 100644
--- a/usr.sbin/pkg_add/OpenBSD/PkgCreate.pm
+++ b/usr.sbin/pkg_add/OpenBSD/PkgCreate.pm
@@ -1,6 +1,6 @@
 #! /usr/bin/perl
 # ex:ts=8 sw=4:
-# $OpenBSD: PkgCreate.pm,v 1.164 2019/11/07 15:36:51 espie Exp $
+# $OpenBSD: PkgCreate.pm,v 1.165 2020/01/09 11:01:25 espie Exp $
 #
 # Copyright (c) 2003-2014 Marc Espie <espie@openbsd.org>
 #
@@ -990,24 +990,33 @@ sub ask_tree
 		$state->fatal("cannot fork: $!");
 	}
 	if ($pid == 0) {
-		# make things debuggable because this child doesn't matter
-		$DB::inhibit_exit = 0;
-		chdir $portsdir or exit 2;
-		open STDERR, ">>", $errors;
 		$ENV{FULLPATH} = 'Yes';
 		delete $ENV{FLAVOR};
 		delete $ENV{SUBPACKAGE};
 		$ENV{SUBDIR} = $pkgpath;
 		$ENV{ECHO_MSG} = ':';
+
+		if (!chdir $portsdir) {
+			$state->errsay("Can't chdir #1: #2", $portsdir, $!);
+			exit(2);
+		}
+		open STDERR, ">>", $errors;
+		# make sure the child starts with a single identity
+		$( = $); $< = $>;
 		# XXX we're already running as ${BUILD_USER}
 		# so we can't do this again
 		push(@action, 'PORTS_PRIVSEP=No');
+		$DB::inhibit_exit = 0;
 		exec $make ('make', @action);
 	}
 	my $plist = OpenBSD::PackingList->read($fh, $data);
+	while(<$fh>) {	# XXX avoid spurious errors from child
+	}
 	close($fh);
 	if ($? != 0) {
-		$state->errsay("child failed: #1", $state->child_error);
+		$state->errsay("child running '#2' failed: #1", 
+		    $state->child_error,
+		    join(' ', 'make', @action));
 		if (open my $fh, '<', $errors) {
 			while(<$fh>) {
 				$state->errprint("#1", $_);