Auto merge of #3320 - str4d:macos-tests, r=bitcartel

Fix MacOS tests

Includes code cherry-picked from upstream PR bitcoin/bitcoin#8270.

src/test/bitcoin-util-test.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright 2014 BitPay, Inc.
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.

src/test/buildenv.py.in

@@ -1,2 +1,2 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 exeext="@EXEEXT@"

src/wallet/gtest/test_wallet.cpp

@@ -581,7 +581,7 @@ TEST(wallet_tests, cached_witnesses_empty_chain) {
 
     // Until #1302 is implemented, this should triggger an assertion
     EXPECT_DEATH(wallet.DecrementNoteWitnesses(&index),
-                 "Assertion `nWitnessCacheSize > 0' failed.");
+                 ".*nWitnessCacheSize > 0.*");
 }
 
 TEST(wallet_tests, cached_witnesses_chain_tip) {