From 910d4bae24b6d399253985740cbd6b63823f58f5 Mon Sep 17 00:00:00 2001
From: "J. Lewis Muir" <jlmuir@imca-cat.org>
Date: Mon, 20 Jul 2015 15:10:49 -0500
Subject: [PATCH] pkgtools/pbulk: delete xcrun cache file before unprivileged
 su

On OS X, before running certain phases of a package build as the
unprivileged user via su, delete the xcrun cache file of the privileged
user to avoid "permission denied" errors in the package build logs when
the unprivileged xcrun program tries to overwrite the existing cache
file of the privileged user.

This is needed because, on OS X Yosemite with Command Line Tools
(10.10) for Xcode 6.4, the xcrun program creates an xcrun_db cache
file.  This cache file will be created when run as the privileged user.
Unfortunately, when xcrun is run as the unprivileged user via su, it
will try to overwrite the cache file of the privileged user and will
fail because it does not have the needed permissions.  This results
in the configure and build logs being littered with messages like the
following (the program name, "gm4", will vary):

  gm4: error: couldn't replace cache file '/var/tmp/xcrun_db' with newly
  written file '/var/tmp/xcrun_db-QqnQCjPl' (errno=Permission denied)
---
 pkgtools/pbulk/files/pbulk/scripts/pkg-build | 27 +++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/pkgtools/pbulk/files/pbulk/scripts/pkg-build b/pkgtools/pbulk/files/pbulk/scripts/pkg-build
index 5348c07dec3b2..150245d025e9f 100755
--- a/pkgtools/pbulk/files/pbulk/scripts/pkg-build
+++ b/pkgtools/pbulk/files/pbulk/scripts/pkg-build
@@ -65,8 +65,33 @@ cleanup() {
 	exit 1
 }
 
+delete_xcrun_cache() {
+	local xcrun_bin xcrun_db_tmp
+	if [ -z ${xcrun_db+x} ]; then
+		xcrun_db=''
+		xcrun_bin=`which xcrun`
+		[ $? -eq 0 ] || return
+		[ -n "$xcrun_bin" ] || return
+		xcrun_db_tmp=`{ "$xcrun_bin" -v true 2>&1; } | \
+		    grep ' xcrun_db = .*' | head -n 1`
+		xcrun_db_tmp=${xcrun_db_tmp#*"'"}
+		xcrun_db_tmp=${xcrun_db_tmp%"'"}
+		[ "X${xcrun_db_tmp##*/}" = Xxcrun_db ] || return
+		xcrun_db="$xcrun_db_tmp"
+	fi
+	[ -n "$xcrun_db" ] && rm -f "$xcrun_db"
+}
+
+pre_run_su() {
+	# On OS X, if the privileged user's xcrun cache file exists, delete
+	# it because the xcrun invoked as the unprivileged user via su may
+	# try to replace it and fail because it does not have appropriate
+	# permissions.
+	delete_xcrun_cache
+}
+
 run_direct() { "$@"; }
-run_su() { su ${unprivileged_user} -c '"$@"' make "$@"; }
+run_su() { pre_run_su; su ${unprivileged_user} -c '"$@"' make "$@"; }
 
 run_make() {
 	local run_cmd