Merge pull request #7884 from uranusjr/new-resolver-ci

Add Travis job against the new resolver

.travis.yml

@@ -10,6 +10,7 @@ addons:
 stages:
 - primary
 - secondary
+- experimental
 
 jobs:
   include:
@@ -51,7 +52,19 @@ jobs:
     - env: GROUP=2
       python: 3.5
 
+    # Test experimental stuff that are not part of the standard pip usage.
+    # Helpful for developers working on them to see how they're doing.
+    - stage: experimental
+      env:
+      - GROUP=1
+      - PIP_UNSTABLE_FEATURE=resolver
+    - env:
+      - GROUP=2
+      - PIP_UNSTABLE_FEATURE=resolver
+
   fast_finish: true
+  allow_failures:
+    - stage: experimental
 
 before_install: tools/travis/setup.sh
 install: travis_retry tools/travis/install.sh

tox.ini

@@ -11,7 +11,14 @@ pip = python {toxinidir}/tools/tox_pip.py
 
 [testenv]
 # Remove USERNAME once we drop PY2.
-passenv = CI GIT_SSL_CAINFO USERNAME HTTP_PROXY HTTPS_PROXY NO_PROXY
+passenv =
+    CI
+    GIT_SSL_CAINFO
+    USERNAME
+    HTTP_PROXY
+    HTTPS_PROXY
+    NO_PROXY
+    PIP_UNSTABLE_FEATURE
 setenv =
     # This is required in order to get UTF-8 output inside of the subprocesses
     # that our tests use.