--- a/taskcluster/ci/legacy/tasks/lint.yml
+++ b/taskcluster/ci/legacy/tasks/lint.yml
@@ -18,26 +18,29 @@ task:
   workerType: b2gtest
   provisionerId: aws-provisioner-v1
   schedulerId: task-graph-scheduler
 
   routes:
     - 'index.gecko.v1.{{project}}.revision.linux.{{head_rev}}.{{build_name}}'
     - 'index.gecko.v1.{{project}}.latest.linux.{{build_name}}'
   scopes:
-    # Nearly all of our build tasks use tc-vcs so just include the scope across
-    # the board.
-    - 'docker-worker:cache:level-{{level}}-{{project}}-tc-vcs'
+    - 'docker-worker:cache:level-{{level}}-hg-shared'
 
   payload:
     # Thirty minutes should be enough for lint checks
     maxRunTime: 1800
 
     cache:
-      level-{{level}}-{{project}}-tc-vcs: '/home/worker/.tc-vcs'
+      level-{{level}}-hg-shared: '/home/worker/hg-shared'
+
+    env:
+      GECKO_BASE_REPOSITORY: '{{base_repository}}'
+      GECKO_HEAD_REPOSITORY: '{{head_repository}}'
+      GECKO_HEAD_REV: '{{head_rev}}'
 
   extra:
     build_product: '{{build_product}}'
     build_name: {{build_name}}
     build_type: {{build_type}}
     index:
       rank: {{rank}}
     treeherder:

--- a/taskcluster/ci/legacy/tasks/tests/eslint-gecko.yml
+++ b/taskcluster/ci/legacy/tasks/tests/eslint-gecko.yml
@@ -15,20 +15,21 @@ task:
   payload:
     image:
       type: 'task-image'
       path: 'public/image.tar'
       taskId:
         task-reference: "<docker-image>"
 
     command:
+      - /home/worker/bin/checkout-gecko-and-run
+      - gecko
       - bash
       - -cx
       - >
-          tc-vcs checkout ./gecko {{base_repository}} {{head_repository}} {{head_rev}} {{head_ref}} &&
           cd gecko/tools/lint/eslint &&
           /build/tooltool.py fetch -m manifest.tt &&
           tar xvfz eslint.tar.gz &&
           rm eslint.tar.gz &&
           cd ../../.. &&
           tools/lint/eslint/node_modules/.bin/eslint --quiet --plugin html --ext [.js,.jsm,.jsx,.xml,.html] -f tools/lint/eslint-formatter .
 
   extra:

--- a/taskcluster/ci/legacy/tasks/tests/mozlint-flake8.yml
+++ b/taskcluster/ci/legacy/tasks/tests/mozlint-flake8.yml
@@ -13,20 +13,21 @@ task:
     description: 'Python flake8 linter'
   payload:
     image:
       type: 'task-image'
       path: 'public/image.tar'
       taskId:
         task-reference: "<docker-image>"
     command:
+      - /home/worker/bin/checkout-gecko-and-run
+      - gecko
       - bash
       - -cx
       - >
-          tc-vcs checkout ./gecko {{base_repository}} {{head_repository}} {{head_rev}} {{head_ref}} &&
           cd gecko &&
           ./mach lint -l flake8 -f treeherder
   extra:
     locations:
       build: null
       tests: null
     treeherder:
       machine:

--- a/taskcluster/ci/legacy/tasks/tests/taskgraph-tests.yml
+++ b/taskcluster/ci/legacy/tasks/tests/taskgraph-tests.yml
@@ -13,20 +13,21 @@ task:
     description: 'Run test suite for taskcluster/taskgraph'
   payload:
     image:
       type: 'task-image'
       path: 'public/image.tar'
       taskId:
         task-reference: "<docker-image>"
     command:
+      - /home/worker/bin/checkout-gecko-and-run
+      - gecko
       - bash
       - -cx
       - >
-          tc-vcs checkout ./gecko {{base_repository}} {{head_repository}} {{head_rev}} {{head_ref}} &&
           cd gecko &&
           ./mach taskgraph python-tests
   extra:
     locations:
       build: null
       tests: null
     treeherder:
       machine:

--- a/testing/docker/lint/system-setup.sh
+++ b/testing/docker/lint/system-setup.sh
@@ -36,56 +36,44 @@ cd /build
 ###
 # ESLint Setup
 ###
 
 # install node
 
 # For future reference things like this don't need to be uploaded to tooltool, as long
 # as we verify the hash, we can download it from the external net.
+cd /setup
 tooltool_fetch <<'EOF'
 [
 {
     "size": 8310316,
     "digest": "95f4fa3d9b215348393dfac4a1c5eff72e9ef85dca38eb69cc8e6c1fe5aada0136c3b182dc04ed5c19fb69f0ac7df85d9c4045b9eb382fcb545b0ccacfece25b",
     "algorithm": "sha512",
     "filename": "node-v4.4.5-linux-x64.tar.xz"
 }
 ]
 EOF
 tar -C /usr/local --strip-components 1 -xJ < node-*.tar.xz
 node -v  # verify
 npm -v
 
-# install taskcluster-vcs@2.3.12
-tooltool_fetch <<'EOF'
-[
-{
-"size": 6282161,
-"visibility": "public",
-"digest": "a781a96e596f6403eca6ec2300adb9c1a396659393e16993c66f98a658050e557bc681d521f70b50c1162aa4b435274e0098ffcbd37cbe969c0e4f69be19a1e0",
-"algorithm": "sha512",
-"filename": "taskcluster-vcs-v2.3.12.tar.gz"
-}
-]
-EOF
-npm install -g taskcluster-vcs-v2.3.12.tar.gz
-
-
 ###
 # Flake8 Setup
 ###
 
+cd /setup
 cat >requirements.txt <<'EOF'
 flake8==2.5.4 \
   --hash=sha256:fb5a67af4024622287a76abf6b7fe4fb3cfacf765a790976ce64f52c44c88e4a
 mccabe==0.4.0 \
   --hash=sha256:cbc2938f6c01061bc6d21d0c838c2489664755cb18676f0734d7617f4577d09e
 pep8==1.7.0 \
   --hash=sha256:4fc2e478addcf17016657dff30b2d8d611e8341fac19ccf2768802f6635d7b8a
 pyflakes==1.2.3 \
   --hash=sha256:e87bac26c62ea5b45067cc89e4a12f56e1483f1f2cda17e7c9b375b9fd2f40da
 EOF
 
 pip install --require-hashes -r requirements.txt
 
 cd /
 rm -rf /setup
+

--- a/testing/docker/recipes/install-mercurial.sh
+++ b/testing/docker/recipes/install-mercurial.sh
@@ -22,21 +22,38 @@ tooltool_fetch <<EOF
     "algorithm": "sha512",
     "filename": "mercurial-common_3.8.4_all.deb"
 }
 ]
 EOF
 
 dpkg -i mercurial-common_3.8.4_all.deb mercurial_3.8.4_amd64.deb
 
+mkdir -p /usr/local/mercurial
+cd /usr/local/mercurial
+tooltool_fetch <<'EOF'
+[
+{
+    "size": 11849,
+    "digest": "c88d9b8afd6649bd28bbacfa654ebefec8087a01d1662004aae088d485edeb03a92df1193d1310c0369d7721f475b974fcd4a911428ec65936f7e40cf1609c49",
+    "algorithm": "sha512",
+    "filename": "robustcheckout.py"
+}
+]
+EOF
+chmod 644 /usr/local/mercurial/robustcheckout.py
+
 mkdir -p /etc/mercurial
 cat >/etc/mercurial/hgrc <<EOF
 # By default the progress bar starts after 3s and updates every 0.1s. We
 # change this so it shows and updates every 1.0s.
 [progress]
 delay = 1.0
 refresh = 1.0
 
 [web]
 cacerts = /etc/ssl/certs/ca-certificates.crt
+
+[extensions]
+robustcheckout = /usr/local/mercurial/robustcheckout.py
 EOF
 
 chmod 644 /etc/mercurial/hgrc