diff --git a/3rdparty/python/constraints.txt b/3rdparty/python/constraints.txt
new file mode 100644
index 00000000000..0aa3c7b4354
--- /dev/null
+++ b/3rdparty/python/constraints.txt
@@ -0,0 +1,33 @@
+# Generated by build-support/bin/generate_lockfile.sh on Mon Aug 10 13:36:18 EDT 2020
+ansicolors==1.1.8
+beautifulsoup4==4.6.3
+certifi==2020.6.20
+cffi==1.14.1
+chardet==3.0.4
+cryptography==3.0
+dataclasses==0.6
+fasteners==0.15
+idna==2.10
+monotonic==1.5
+mypy==0.782
+mypy-extensions==0.4.3
+packaging==20.4
+pathspec==0.8.0
+pex==2.1.14
+pip==19.0.3
+psutil==5.7.0
+pycparser==2.20
+pyOpenSSL==19.1.0
+pyparsing==2.4.7
+pystache==0.5.4
+python-Levenshtein==0.12.0
+PyYAML==5.3.1
+requests==2.24.0
+setproctitle==1.1.10
+setuptools==49.2.0
+six==1.15.0
+toml==0.10.1
+typed-ast==1.4.1
+typing-extensions==3.7.4.2
+urllib3==1.25.10
+www-authenticate==0.9.2
diff --git a/build-support/bin/generate_lockfile.sh b/build-support/bin/generate_lockfile.sh
new file mode 100755
index 00000000000..9ee4195b955
--- /dev/null
+++ b/build-support/bin/generate_lockfile.sh
@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+constraints_file=3rdparty/python/constraints.txt
+
+VENV=$(mktemp -d -t pants_lockfile_venv.XXXXX)
+python3 -m venv "${VENV}"
+"${VENV}/bin/pip" install -r <(./pants --tag=-lockfile_ignore dependencies --type=3rdparty ::)
+echo "# Generated by build-support/bin/generate_lockfile.sh on $(date)" > "${constraints_file}"
+"${VENV}/bin/pip" freeze --all >> "${constraints_file}"
diff --git a/pants.toml b/pants.toml
index c785d7fd6d6..38f8fe9521b 100644
--- a/pants.toml
+++ b/pants.toml
@@ -52,9 +52,8 @@ root_patterns = [
 ]
 
 [python-setup]
-# TODO: Set up an actual lockfile. For now we just "lock" our requirements.txt to itself,
-#  so we can use --python-setup-resolve-all-constraints (which requires a lockfile).
-requirement_constraints = "3rdparty/python/requirements.txt"
+requirement_constraints = "3rdparty/python/constraints.txt"
+resolve_all_constraints = true
 
 [black]
 config = "pyproject.toml"
diff --git a/pants.travis-ci.toml b/pants.travis-ci.toml
index 347ff2f2c47..5e4f1b49100 100644
--- a/pants.travis-ci.toml
+++ b/pants.travis-ci.toml
@@ -1,9 +1,3 @@
-[DEFAULT]
-# If we use typical default process parallelism tied to core count, we see too many cores under
-# travis and either get oomkilled from launching too many processes with too much total memory
-# overhead or else just generally thrash the container and slow things down.
-travis_parallelism = 4
-
 [GLOBAL]
 # Override color support detection - we want colors and Travis supports them.
 colors = true
@@ -14,8 +8,6 @@ dynamic_ui = false
 # now in order to smooth off rough edges locally.
 pantsd = false
 
-process_execution_local_parallelism = "%(travis_parallelism)s"
-
 [python-setup]
 # TODO: See https://github.com/pantsbuild/pants/issues/9964
 resolver_jobs = 2
diff --git a/src/python/pants/backend/python/typecheck/mypy/BUILD b/src/python/pants/backend/python/typecheck/mypy/BUILD
index a3eddcb0336..ca4a609ff27 100644
--- a/src/python/pants/backend/python/typecheck/mypy/BUILD
+++ b/src/python/pants/backend/python/typecheck/mypy/BUILD
@@ -6,5 +6,5 @@ python_library()
 python_integration_tests(
   name='integration',
   uses_pants_run=False,
-  timeout=180,
+  timeout=300,
 )
diff --git a/src/python/pants/base/BUILD b/src/python/pants/base/BUILD
index 621b083ba9d..0dbc14fd495 100644
--- a/src/python/pants/base/BUILD
+++ b/src/python/pants/base/BUILD
@@ -40,5 +40,5 @@ python_integration_tests(
     'testprojects/src/python:unicode_directory',
   ],
   uses_pants_run=True,
-  timeout=120,
+  timeout=180,
 )
diff --git a/src/python/pants/init/BUILD b/src/python/pants/init/BUILD
index bfa81aaaa08..677254b8b1c 100644
--- a/src/python/pants/init/BUILD
+++ b/src/python/pants/init/BUILD
@@ -30,5 +30,5 @@ python_integration_tests(
   name="integration",
   uses_pants_run=True,
   # TODO(#10504): Lower this to ~120 once fixed.
-  timeout=450,
+  timeout=600,
 )
diff --git a/testprojects/pants-plugins/src/python/test_pants_plugin/BUILD b/testprojects/pants-plugins/src/python/test_pants_plugin/BUILD
index c406ddda835..f36e126d6ca 100644
--- a/testprojects/pants-plugins/src/python/test_pants_plugin/BUILD
+++ b/testprojects/pants-plugins/src/python/test_pants_plugin/BUILD
@@ -13,5 +13,6 @@ python_distribution(
     namespace_packages=[
       'test_pants_plugin',
     ],
-  )
+  ),
+  tags=['lockfile_ignore'],
 )
diff --git a/testprojects/src/python/bad_requirements/BUILD b/testprojects/src/python/bad_requirements/BUILD
index 811a9f27a12..53bca8dc360 100644
--- a/testprojects/src/python/bad_requirements/BUILD
+++ b/testprojects/src/python/bad_requirements/BUILD
@@ -5,11 +5,12 @@ python_requirement_library(
   name='badreq',
   requirements=[
     python_requirement('badreq==99.99.99')
-  ]
+  ],
 )
 
 python_binary(
   name='use_badreq',
   dependencies=[':badreq'],
   entry_point='bad_requirements.use_badreq',
+  tags=['lockfile_ignore'],
 )
diff --git a/tests/python/pants_test/integration/BUILD b/tests/python/pants_test/integration/BUILD
index c4cc0933197..38505a14ddd 100644
--- a/tests/python/pants_test/integration/BUILD
+++ b/tests/python/pants_test/integration/BUILD
@@ -52,13 +52,14 @@ python_integration_tests(
     'testprojects/tests/python/pants:build_parsing_directory',
   ],
   uses_pants_run=True,
-  timeout = 180,
+  timeout = 240,
 )
 
 python_integration_tests(
   name = 'prelude_integration',
   sources = ['test_prelude_integration.py'],
   uses_pants_run=True,
+  timeout = 180,
 )
 
 python_integration_tests(