'spack install': make conflict messages as verbose as 'spack spec' (#6436)

"spack spec" was providing helpful error information about conflicts
that was missing from "spack install", this updates "spack install"
to provide the same information.

lib/spack/spack/cmd/__init__.py

@@ -127,7 +127,12 @@ def parse_specs(args, **kwargs):
         sys.exit(1)
 
     except spack.spec.SpecError as e:
-        tty.error(e.message)
+
+        msgs = [e.message]
+        if e.long_message:
+            msgs.append(e.long_message)
+
+        tty.error(*msgs)
         sys.exit(1)
 
 

lib/spack/spack/test/cmd/install.py

@@ -33,7 +33,7 @@
 import spack
 import spack.cmd.install
 from spack.spec import Spec
-from spack.main import SpackCommand
+from spack.main import SpackCommand, SpackCommandError
 
 install = SpackCommand('install')
 
@@ -234,3 +234,14 @@ def test_install_overwrite(
     assert os.path.exists(spec.prefix)
     assert fs.hash_directory(spec.prefix) == expected_md5
     assert fs.hash_directory(spec.prefix) != bad_md5
+
+
+@pytest.mark.usefixtures(
+    'builtin_mock', 'mock_archive', 'mock_fetch', 'config', 'install_mockery',
+)
+def test_install_conflicts(conflict_spec):
+    # Make sure that spec with conflicts exit with 1
+    with pytest.raises(SpackCommandError):
+        install(conflict_spec)
+
+    assert install.returncode == 1

lib/spack/spack/test/concretize.py

@@ -94,19 +94,6 @@ def spec(request):
     return request.param
 
 
-@pytest.fixture(
-    params=[
-        'conflict%clang',
-        'conflict%clang+foo',
-        'conflict-parent%clang',
-        'conflict-parent@0.9^conflict~foo'
-    ]
-)
-def conflict_spec(request):
-    """Spec to be concretized"""
-    return request.param
-
-
 @pytest.mark.usefixtures('config', 'builtin_mock')
 class TestConcretize(object):
     def test_concretize(self, spec):

lib/spack/spack/test/conftest.py

@@ -690,3 +690,22 @@ def repo_for_pkg(self, name):
         import collections
         Repo = collections.namedtuple('Repo', ['namespace'])
         return Repo('mockrepo')
+
+##########
+# Specs of various kind
+##########
+
+
+@pytest.fixture(
+    params=[
+        'conflict%clang',
+        'conflict%clang+foo',
+        'conflict-parent%clang',
+        'conflict-parent@0.9^conflict~foo'
+    ]
+)
+def conflict_spec(request):
+    """Specs which violate constraints specified with the "conflicts"
+    directive in the "conflict" package.
+    """
+    return request.param