Workaround cpu detection on Travis CI

changelog/316.bugfix

@@ -0,0 +1 @@
+Workaround cpu detection on Travis CI

testing/test_plugin.py

@@ -45,6 +45,11 @@ def test_auto_detect_cpus(testdir, monkeypatch):
     config = testdir.parseconfigure("-nauto")
     assert config.getoption('numprocesses') == 99
 
+    monkeypatch.delattr(os, 'sched_getaffinity', raising=False)
+    monkeypatch.setenv('TRAVIS', 'true')
+    config = testdir.parseconfigure("-nauto")
+    assert config.getoption('numprocesses') == 2
+
 
 def test_boxed_with_collect_only(testdir):
     from xdist.plugin import pytest_cmdline_main as check_options

xdist/plugin.py

@@ -1,25 +1,34 @@
+import os
+
 import py
 import pytest
 
 
-def parse_numprocesses(s):
-    if s == 'auto':
+def auto_detect_cpus():
+    try:
+        from os import sched_getaffinity
+    except ImportError:
+        if os.environ.get('TRAVIS') == 'true':
+            # workaround https://bitbucket.org/pypy/pypy/issues/2375
+            return 2
         try:
-            from os import sched_getaffinity
+            from os import cpu_count
         except ImportError:
-            try:
-                from os import cpu_count
-            except ImportError:
-                from multiprocessing import cpu_count
-        else:
-            def cpu_count():
-                return len(sched_getaffinity(0))
+            from multiprocessing import cpu_count
+    else:
+        def cpu_count():
+            return len(sched_getaffinity(0))
 
-        try:
-            n = cpu_count()
-        except NotImplementedError:
-            return 1
-        return n if n else 1
+    try:
+        n = cpu_count()
+    except NotImplementedError:
+        return 1
+    return n if n else 1
+
+
+def parse_numprocesses(s):
+    if s == 'auto':
+        return auto_detect_cpus()
     else:
         return int(s)