diff --git a/tools/tryselect/mach_commands.py b/tools/tryselect/mach_commands.py
index 9dd13352ee15..9ddd40e304b0 100644
--- a/tools/tryselect/mach_commands.py
+++ b/tools/tryselect/mach_commands.py
@@ -156,15 +156,22 @@ class TrySelect(MachCommandBase):
 
     def handle_try_config(self, **kwargs):
         from tryselect.util.dicttools import merge
+
+        to_validate = []
         kwargs.setdefault('try_config', {})
         for cls in six.itervalues(self.parser.task_configs):
             try_config = cls.try_config(**kwargs)
             if try_config is not None:
+                to_validate.append(cls)
                 kwargs['try_config'] = merge(kwargs['try_config'], try_config)
 
             for name in cls.dests:
                 del kwargs[name]
 
+        # Validate task_configs after they have all been parsed to avoid
+        # depending on the order they were processed.
+        for cls in to_validate:
+            cls.validate(**kwargs)
         return kwargs
 
     def run(self, **kwargs):
diff --git a/tools/tryselect/task_config.py b/tools/tryselect/task_config.py
index 1338dab4b36e..7563d9f660a8 100644
--- a/tools/tryselect/task_config.py
+++ b/tools/tryselect/task_config.py
@@ -47,6 +47,9 @@ class TryConfig(object):
     def try_config(self, **kwargs):
         pass
 
+    def validate(self, **kwargs):
+        pass
+
 
 class Artifact(TryConfig):
 
@@ -112,17 +115,13 @@ class Pernosco(TryConfig):
             return
 
         if pernosco:
-            if not kwargs['no_artifact'] and (kwargs['artifact'] or Artifact.is_artifact_build()):
-                print("Pernosco does not support artifact builds at this time. "
-                      "Please try again with '--no-artifact'.")
-                sys.exit(1)
-
             try:
                 # The Pernosco service currently requires a Mozilla e-mail address to
                 # log in. Prevent people with non-Mozilla addresses from using this
                 # flag so they don't end up consuming time and resources only to
                 # realize they can't actually log in and see the reports.
-                output = subprocess.check_output(['ssh', '-G', 'hg.mozilla.org']).splitlines()
+                cmd = ['ssh', '-G', 'hg.mozilla.org']
+                output = subprocess.check_output(cmd, universal_newlines=True).splitlines()
                 address = [l.rsplit(' ', 1)[-1] for l in output if l.startswith('user')][0]
                 if not address.endswith('@mozilla.com'):
                     print(dedent("""\
@@ -137,7 +136,7 @@ class Pernosco(TryConfig):
                 print("warning: failed to detect current user for 'hg.mozilla.org'")
                 print("Pernosco requires a Mozilla e-mail address to view its reports.")
                 while True:
-                    answer = raw_input("Do you have an @mozilla.com address? [Y/n]: ").lower()
+                    answer = input("Do you have an @mozilla.com address? [Y/n]: ").lower()
                     if answer == 'n':
                         sys.exit(1)
                     elif answer == 'y':
@@ -149,6 +148,12 @@ class Pernosco(TryConfig):
             }
         }
 
+    def validate(self, **kwargs):
+        if kwargs['try_config'].get('use-artifact-builds'):
+            print("Pernosco does not support artifact builds at this time. "
+                  "Please try again with '--no-artifact'.")
+            sys.exit(1)
+
 
 class Path(TryConfig):
 
diff --git a/tools/tryselect/test/test_task_configs.py b/tools/tryselect/test/test_task_configs.py
index baa0a7e3633f..df6acda4b7a1 100644
--- a/tools/tryselect/test/test_task_configs.py
+++ b/tools/tryselect/test/test_task_configs.py
@@ -9,8 +9,10 @@ from argparse import ArgumentParser
 
 import mozunit
 import pytest
+import subprocess
+from textwrap import dedent
 
-from tryselect.task_config import all_task_configs
+from tryselect.task_config import all_task_configs, Pernosco
 
 
 # task configs have a list of tests of the form (input, expected)
@@ -34,6 +36,9 @@ TASK_CONFIG_TESTS = {
          {'env': {'MOZHARNESS_TEST_PATHS': '{"xpcshell": ["dom/indexedDB", "testing"]}'}}),
         (['invalid/path'], SystemExit),
     ],
+    'pernosco': [
+        ([], None),
+    ],
     'rebuild': [
         ([], None),
         (['--rebuild', '10'], {'rebuild': 10}),
@@ -89,5 +94,32 @@ def test_task_configs(config_patch_resolver, task_config, args, expected):
         assert cfg.try_config(**vars(args)) == expected
 
 
+@pytest.fixture
+def patch_pernosco_email_check(monkeypatch):
+
+    def inner(val):
+
+        def fake_check_output(*args, **kwargs):
+            return val
+
+        monkeypatch.setattr(subprocess, 'check_output', fake_check_output)
+
+    return inner
+
+
+def test_pernosco(patch_pernosco_email_check):
+    patch_pernosco_email_check(dedent("""
+        user foobar@mozilla.com
+        hostname hg.mozilla.com
+    """))
+
+    parser = ArgumentParser()
+
+    cfg = Pernosco()
+    cfg.add_arguments(parser)
+    args = parser.parse_args(['--pernosco'])
+    assert cfg.try_config(**vars(args)) == {"env": {"PERNOSCO": "1"}}
+
+
 if __name__ == '__main__':
     mozunit.main()