Add upper bound on number of processes to run for CI runs as this can

  help control flakiness. ``36`` workers (unbounded ``-n auto``) seems
  to be too much to account for tests that rely on the ``dev.period``
  block processing time.

Author: fselmo

tests/integration/go_ethereum/conftest.py

@@ -95,7 +95,7 @@ def base_geth_command_arguments(geth_binary, datadir):
         datadir,
         "--dev",
         "--dev.period",
-        "1",
+        "3",
         "--password",
         os.path.join(datadir, "keystore", "pw.txt"),
         # in order to raise on underpriced transactions, ``txpool.nolocals`` is now

tox.ini

@@ -22,15 +22,15 @@ usedevelop=True
 commands=
     core: pytest {posargs:tests/core -m "not asyncio"}
     core_async: pytest {posargs:tests/core -m asyncio}
-    ens: pytest {posargs:tests/ens --ignore=tests/ens/normalization/test_normalize_name_ensip15.py -n auto}
-    ensip15: pytest {posargs:tests/ens/normalization/test_normalize_name_ensip15.py -q -n auto}
-    integration-goethereum-ipc: pytest {posargs:tests/integration/go_ethereum/test_goethereum_ipc.py -k "not Async" -n auto}
-    integration-goethereum-ipc_async: pytest {posargs:tests/integration/go_ethereum/test_goethereum_ipc.py -k Async -n auto}
-    integration-goethereum-http: pytest {posargs:tests/integration/go_ethereum/test_goethereum_http.py -k "not Async" -n auto}
-    integration-goethereum-http_async: pytest {posargs:tests/integration/go_ethereum/test_goethereum_http.py -k Async -n auto}
-    integration-goethereum-legacy_ws: pytest {posargs:tests/integration/go_ethereum/test_goethereum_legacy_ws.py -n auto}
-    integration-goethereum-ws: pytest {posargs:tests/integration/go_ethereum/test_goethereum_ws -n auto}
-    integration-ethtester: pytest {posargs:tests/integration/test_ethereum_tester.py -n auto}
+    ens: pytest {posargs:tests/ens --ignore=tests/ens/normalization/test_normalize_name_ensip15.py -n auto --maxprocesses=15}
+    ensip15: pytest {posargs:tests/ens/normalization/test_normalize_name_ensip15.py -q -n auto --maxprocesses=15}
+    integration-goethereum-ipc: pytest {posargs:tests/integration/go_ethereum/test_goethereum_ipc.py -k "not Async" -n auto --maxprocesses=15}
+    integration-goethereum-ipc_async: pytest {posargs:tests/integration/go_ethereum/test_goethereum_ipc.py -k Async -n auto --maxprocesses=15}
+    integration-goethereum-http: pytest {posargs:tests/integration/go_ethereum/test_goethereum_http.py -k "not Async" -n auto --maxprocesses=15}
+    integration-goethereum-http_async: pytest {posargs:tests/integration/go_ethereum/test_goethereum_http.py -k Async -n auto --maxprocesses=15}
+    integration-goethereum-legacy_ws: pytest {posargs:tests/integration/go_ethereum/test_goethereum_legacy_ws.py -n auto --maxprocesses=15}
+    integration-goethereum-ws: pytest {posargs:tests/integration/go_ethereum/test_goethereum_ws -n auto --maxprocesses=15}
+    integration-ethtester: pytest {posargs:tests/integration/test_ethereum_tester.py -n auto --maxprocesses=15}
     docs: make check-docs-ci
 deps =
     .[test]