From 22bedf627fb97e0d2f59200e9dc7c41a631a925d Mon Sep 17 00:00:00 2001
From: Vasileios Karakasis <karakasis@cscs.ch>
Date: Sat, 26 Sep 2020 22:58:56 +0200
Subject: [PATCH] Restore environment correctly in case of module load failures

---
 reframe/core/runtime.py        |  8 ++++++--
 unittests/test_environments.py | 21 +++++++++++++++++----
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/reframe/core/runtime.py b/reframe/core/runtime.py
index 4c74dcd95f..5e4132e4e7 100644
--- a/reframe/core/runtime.py
+++ b/reframe/core/runtime.py
@@ -220,8 +220,12 @@ def loadenv(*environs):
 
 
 def emit_loadenv_commands(*environs):
-    env_snapshot, commands = loadenv(*environs)
-    env_snapshot.restore()
+    env_snapshot = snapshot()
+    try:
+        _, commands = loadenv(*environs)
+    finally:
+        env_snapshot.restore()
+
     return commands
 
 
diff --git a/unittests/test_environments.py b/unittests/test_environments.py
index ac61f062ea..3d5029842d 100644
--- a/unittests/test_environments.py
+++ b/unittests/test_environments.py
@@ -3,6 +3,7 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+import contextlib
 import os
 import pytest
 
@@ -225,8 +226,8 @@ def test_env_immutability(base_environ, env0):
         prgenv.ldflags = ['-lm']
 
 
-def test_env_emit_load_commands(base_environ, user_runtime,
-                                modules_system, env0):
+def test_emit_loadenv_commands(base_environ, user_runtime,
+                               modules_system, env0):
     ms = rt.runtime().modules_system
     expected_commands = [
         ms.emit_load_commands('testmod_foo')[0],
@@ -237,8 +238,8 @@ def test_env_emit_load_commands(base_environ, user_runtime,
     assert expected_commands == rt.emit_loadenv_commands(env0)
 
 
-def test_env_emit_load_commands_with_confict(base_environ, user_runtime,
-                                             modules_system, env0):
+def test_emit_loadenv_commands_with_confict(base_environ, user_runtime,
+                                            modules_system, env0):
     # Load a conflicting module
     modules_system.load_module('testmod_bar')
     ms = rt.runtime().modules_system
@@ -250,3 +251,15 @@ def test_env_emit_load_commands_with_confict(base_environ, user_runtime,
         'export _var3=${_var1}',
     ]
     assert expected_commands == rt.emit_loadenv_commands(env0)
+
+
+def test_emit_loadenv_failure(user_runtime):
+    snap = rt.snapshot()
+    environ = env.Environment('test', modules=['testmod_foo', 'testmod_xxx'])
+
+    # Suppress the module load error and verify that the original environment
+    # is preserved
+    with contextlib.suppress(EnvironError):
+        rt.emit_loadenv_commands(environ)
+
+    assert rt.snapshot() == snap