diff --git a/.circleci/config.yml b/.circleci/config.yml
index d17f13baadd4..288749974fb3 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -33,26 +33,11 @@ defaults:
 
   - run_build: &run_build
       name: Build
-      command: |
-        set -ex
-        if [ "$CIRCLE_BRANCH" = release -o -n "$CIRCLE_TAG" -o -n "$FORCE_RELEASE" ]; then echo -n > prerelease.txt; else date -u +"nightly.%Y.%-m.%-d" > prerelease.txt; fi
-        echo -n "$CIRCLE_SHA1" > commit_hash.txt
-        mkdir -p build
-        cd build
-        [ -n "$COVERAGE" -a "$CIRCLE_BRANCH" != release -a -z "$CIRCLE_TAG" ] && CMAKE_OPTIONS="$CMAKE_OPTIONS -DCOVERAGE=ON"
-        cmake .. -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE:-Release} $CMAKE_OPTIONS -G "Unix Makefiles"
-        make -j4
+      command: scripts/ci/build.sh
 
   - run_build_ossfuzz: &run_build_ossfuzz
       name: Build_ossfuzz
-      command: |
-        mkdir -p build
-        cd build
-        protoc --proto_path=../test/tools/ossfuzz yulProto.proto --cpp_out=../test/tools/ossfuzz
-        protoc --proto_path=../test/tools/ossfuzz abiV2Proto.proto --cpp_out=../test/tools/ossfuzz
-        protoc --proto_path=../test/tools/ossfuzz solProto.proto --cpp_out=../test/tools/ossfuzz
-        cmake .. -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE:-Release} $CMAKE_OPTIONS
-        make ossfuzz ossfuzz_proto ossfuzz_abiv2 -j4
+      command: scripts/ci/build_ossfuzz.sh
 
   - run_proofs: &run_proofs
       name: Correctness proofs for optimization rules
diff --git a/.github/workflows/buildpack-emscripten.yml b/.github/workflows/buildpack-emscripten.yml
new file mode 100644
index 000000000000..7f22b6554bb2
--- /dev/null
+++ b/.github/workflows/buildpack-emscripten.yml
@@ -0,0 +1,34 @@
+name: buildpack:emscripten
+
+on:
+  pull_request:
+    paths:
+      - '.github/workflows/buildpack-emscripten.yml'
+      - 'scripts/docker/buildpack/Dockerfile.emscripten'
+
+jobs:
+  build:
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      DOCKER_REPOSITORY: docker.pkg.github.com/${{ github.repository }}
+      IMAGE_NAME: buildpack
+      IMAGE_VARIANT: emscripten
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Upgrade ${{ env.IMAGE_NAME }}-${{ env.IMAGE_VARIANT }}
+        run: |
+          echo "${GITHUB_TOKEN}" | docker login docker.pkg.github.com -u "${GITHUB_ACTOR}" --password-stdin
+          scripts/ci/docker_upgrade.sh
+          docker logout docker.pkg.github.com
+
+      - name: comment PR
+        uses: aarlt/comment-on-pr@v1.2.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          msg:  "`${{ env.DOCKER_IMAGE }} ${{ env.DOCKER_REPO_DIGEST }}`."
+          check_for_duplicate_msg: false  # OPTIONAL
diff --git a/.github/workflows/buildpack-ubuntu1604.clang.ossfuzz.yml b/.github/workflows/buildpack-ubuntu1604.clang.ossfuzz.yml
new file mode 100644
index 000000000000..1ca2f1c858bd
--- /dev/null
+++ b/.github/workflows/buildpack-ubuntu1604.clang.ossfuzz.yml
@@ -0,0 +1,34 @@
+name: buildpack:ubuntu1604.clang.ossfuzz
+
+on:
+  pull_request:
+    paths:
+      - '.github/workflows/buildpack-ubuntu1604.clang.ossfuzz.yml'
+      - 'scripts/docker/buildpack/Dockerfile.ubuntu1604.clang.ossfuzz'
+
+jobs:
+  build:
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      DOCKER_REPOSITORY: docker.pkg.github.com/${{ github.repository }}
+      IMAGE_NAME: buildpack
+      IMAGE_VARIANT: ubuntu1604.clang.ossfuzz
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Upgrade ${{ env.IMAGE_NAME }}-${{ env.IMAGE_VARIANT }}
+        run: |
+          echo "${GITHUB_TOKEN}" | docker login docker.pkg.github.com -u "${GITHUB_ACTOR}" --password-stdin
+          scripts/ci/docker_upgrade.sh
+          docker logout docker.pkg.github.com
+
+      - name: comment PR
+        uses: aarlt/comment-on-pr@v1.2.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          msg:  "`${{ env.DOCKER_IMAGE }} ${{ env.DOCKER_REPO_DIGEST }}`."
+          check_for_duplicate_msg: false  # OPTIONAL
diff --git a/.github/workflows/buildpack-ubuntu1804.yml b/.github/workflows/buildpack-ubuntu1804.yml
new file mode 100644
index 000000000000..e0c85ffa1e0f
--- /dev/null
+++ b/.github/workflows/buildpack-ubuntu1804.yml
@@ -0,0 +1,34 @@
+name: buildpack:ubuntu1804
+
+on:
+  pull_request:
+    paths:
+      - '.github/workflows/buildpack-ubuntu1804.yml'
+      - 'scripts/docker/buildpack/Dockerfile.ubuntu1804'
+
+jobs:
+  build:
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      DOCKER_REPOSITORY: docker.pkg.github.com/${{ github.repository }}
+      IMAGE_NAME: buildpack
+      IMAGE_VARIANT: ubuntu1804
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Upgrade ${{ env.IMAGE_NAME }}-${{ env.IMAGE_VARIANT }}
+        run: |
+          echo "${GITHUB_TOKEN}" | docker login docker.pkg.github.com -u "${GITHUB_ACTOR}" --password-stdin
+          scripts/ci/docker_upgrade.sh
+          docker logout docker.pkg.github.com
+
+      - name: comment PR
+        uses: aarlt/comment-on-pr@v1.2.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          msg:  "`${{ env.DOCKER_IMAGE }} ${{ env.DOCKER_REPO_DIGEST }}`."
+          check_for_duplicate_msg: false  # OPTIONAL
diff --git a/.github/workflows/buildpack-ubuntu2004.clang.yml b/.github/workflows/buildpack-ubuntu2004.clang.yml
new file mode 100644
index 000000000000..22164e6f2b32
--- /dev/null
+++ b/.github/workflows/buildpack-ubuntu2004.clang.yml
@@ -0,0 +1,36 @@
+name: buildpack:ubuntu2004.clang
+
+on:
+  pull_request:
+    paths:
+      - '.github/workflows/buildpack-ubuntu2004.clang.yml'
+      - 'scripts/docker/buildpack/Dockerfile.ubuntu2004.clang'
+
+jobs:
+  build:
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      DOCKER_REPOSITORY: docker.pkg.github.com/${{ github.repository }}
+      IMAGE_NAME: buildpack
+      IMAGE_VARIANT: ubuntu2004.clang
+      CC: clang
+      CXX: clang++
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Upgrade ${{ env.IMAGE_NAME }}-${{ env.IMAGE_VARIANT }}
+        run: |
+          echo "${GITHUB_TOKEN}" | docker login docker.pkg.github.com -u "${GITHUB_ACTOR}" --password-stdin
+          scripts/ci/docker_upgrade.sh
+          docker logout docker.pkg.github.com
+
+      - name: comment PR
+        uses: aarlt/comment-on-pr@v1.2.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          msg:  "`${{ env.DOCKER_IMAGE }} ${{ env.DOCKER_REPO_DIGEST }}`."
+          check_for_duplicate_msg: false  # OPTIONAL
diff --git a/.github/workflows/buildpack-ubuntu2004.yml b/.github/workflows/buildpack-ubuntu2004.yml
new file mode 100644
index 000000000000..4ad03a407c11
--- /dev/null
+++ b/.github/workflows/buildpack-ubuntu2004.yml
@@ -0,0 +1,33 @@
+name: buildpack:ubuntu2004
+
+on:
+  pull_request:
+    paths:
+      - '.github/workflows/buildpack-ubuntu2004.yml'
+      - 'scripts/docker/buildpack/Dockerfile.ubuntu2004'
+jobs:
+  build:
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      DOCKER_REPOSITORY: docker.pkg.github.com/${{ github.repository }}
+      IMAGE_NAME: buildpack
+      IMAGE_VARIANT: ubuntu2004
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Upgrade ${{ env.IMAGE_NAME }}-${{ env.IMAGE_VARIANT }}
+        run: |
+          echo "${GITHUB_TOKEN}" | docker login docker.pkg.github.com -u "${GITHUB_ACTOR}" --password-stdin
+          scripts/ci/docker_upgrade.sh
+          docker logout docker.pkg.github.com
+
+      - name: comment PR
+        uses: aarlt/comment-on-pr@v1.2.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          msg:  "`${{ env.DOCKER_IMAGE }} ${{ env.DOCKER_REPO_DIGEST }}`."
+          check_for_duplicate_msg: false  # OPTIONAL
diff --git a/.gitignore b/.gitignore
index 67e4507591ab..749860301975 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,7 +32,7 @@ prerelease.txt
 
 # Build directory
 build/
-build*/
+/build*/
 emscripten_build/
 docs/_build
 __pycache__
diff --git a/scripts/build.sh b/scripts/build.sh
index 6edd60bd9b07..12f7d2e7a04c 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -2,6 +2,11 @@
 set -e
 
 ROOTDIR="$(dirname "$0")/.."
+if [[ "$( cd "$(dirname "$0")" ; pwd -P )" == *".github"* ]]
+then
+    ROOTDIR="/root/project"
+fi
+
 BUILDDIR="${ROOTDIR}/build"
 
 if [[ $# -eq 0 ]]; then
diff --git a/scripts/ci/build.sh b/scripts/ci/build.sh
new file mode 100755
index 000000000000..a731402ff4b0
--- /dev/null
+++ b/scripts/ci/build.sh
@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -ex
+
+ROOTDIR="$(dirname "$0")/../.."
+cd "${ROOTDIR}"
+
+# shellcheck disable=SC2166
+if [ "$CIRCLE_BRANCH" = release -o -n "$CIRCLE_TAG" -o -n "$FORCE_RELEASE" ]; then echo -n >prerelease.txt; else date -u +"nightly.%Y.%-m.%-d" >prerelease.txt; fi
+if [ -n "$CIRCLE_SHA1" ]
+then
+  echo -n "$CIRCLE_SHA1" >commit_hash.txt
+fi
+
+mkdir -p build
+cd build
+
+# shellcheck disable=SC2166
+[ -n "$COVERAGE" -a "$CIRCLE_BRANCH" != release -a -z "$CIRCLE_TAG" ] && CMAKE_OPTIONS="$CMAKE_OPTIONS -DCOVERAGE=ON"
+
+# shellcheck disable=SC2086
+cmake .. -DCMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE:-Release}" $CMAKE_OPTIONS -G "Unix Makefiles"
+make -j4
diff --git a/scripts/ci/build_ossfuzz.sh b/scripts/ci/build_ossfuzz.sh
new file mode 100755
index 000000000000..cdfb141f0a83
--- /dev/null
+++ b/scripts/ci/build_ossfuzz.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -e
+
+ROOTDIR="$(dirname "$0")/../.."
+BUILDDIR="${ROOTDIR}/build"
+
+mkdir -p "${BUILDDIR}"
+cd "${BUILDDIR}"
+
+protoc --proto_path=../test/tools/ossfuzz yulProto.proto --cpp_out=../test/tools/ossfuzz
+protoc --proto_path=../test/tools/ossfuzz abiV2Proto.proto --cpp_out=../test/tools/ossfuzz
+protoc --proto_path=../test/tools/ossfuzz solProto.proto --cpp_out=../test/tools/ossfuzz
+cmake .. -DCMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE:-Release}" -DCMAKE_TOOLCHAIN_FILE=../cmake/toolchains/libfuzzer.cmake
+make ossfuzz ossfuzz_proto ossfuzz_abiv2 -j4
diff --git a/scripts/ci/docker_test_emscripten.sh b/scripts/ci/docker_test_emscripten.sh
new file mode 120000
index 000000000000..6e838fba7fb3
--- /dev/null
+++ b/scripts/ci/docker_test_emscripten.sh
@@ -0,0 +1 @@
+../../scripts/travis-emscripten/build_emscripten.sh
\ No newline at end of file
diff --git a/scripts/ci/docker_test_ubuntu1604.clang.ossfuzz.sh b/scripts/ci/docker_test_ubuntu1604.clang.ossfuzz.sh
new file mode 120000
index 000000000000..86beda7dd2c3
--- /dev/null
+++ b/scripts/ci/docker_test_ubuntu1604.clang.ossfuzz.sh
@@ -0,0 +1 @@
+build_ossfuzz.sh
\ No newline at end of file
diff --git a/scripts/ci/docker_test_ubuntu1804.sh b/scripts/ci/docker_test_ubuntu1804.sh
new file mode 120000
index 000000000000..c07a74de4fb4
--- /dev/null
+++ b/scripts/ci/docker_test_ubuntu1804.sh
@@ -0,0 +1 @@
+build.sh
\ No newline at end of file
diff --git a/scripts/ci/docker_test_ubuntu2004.clang.sh b/scripts/ci/docker_test_ubuntu2004.clang.sh
new file mode 120000
index 000000000000..c07a74de4fb4
--- /dev/null
+++ b/scripts/ci/docker_test_ubuntu2004.clang.sh
@@ -0,0 +1 @@
+build.sh
\ No newline at end of file
diff --git a/scripts/ci/docker_test_ubuntu2004.sh b/scripts/ci/docker_test_ubuntu2004.sh
new file mode 120000
index 000000000000..c07a74de4fb4
--- /dev/null
+++ b/scripts/ci/docker_test_ubuntu2004.sh
@@ -0,0 +1 @@
+build.sh
\ No newline at end of file
diff --git a/scripts/ci/docker_upgrade.sh b/scripts/ci/docker_upgrade.sh
new file mode 100755
index 000000000000..65021387a118
--- /dev/null
+++ b/scripts/ci/docker_upgrade.sh
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+set -e
+
+check_parameters() {
+  echo "-- check_parameters"
+
+  if [ -z "${IMAGE_NAME}" ] || [ -z "${IMAGE_VARIANT}" ] || [ -z "${DOCKER_REPOSITORY}" ]; then
+    echo "\${IMAGE_NAME}, \${IMAGE_VARIANT} and \${DOCKER_REPOSITORY} need to be defined."
+
+    false
+  fi
+}
+
+check_version() {
+  echo "-- check_version"
+
+  git fetch
+  git branch
+  DOCKERFILE="scripts/docker/${IMAGE_NAME}/Dockerfile.${IMAGE_VARIANT}"
+  PREV_VERSION=$(git diff origin/develop HEAD -- "${DOCKERFILE}" | grep -e "-LABEL version=\".*\"" | awk -F"\"" '{ print $2 }')
+  NEXT_VERSION=$(git diff origin/develop HEAD -- "${DOCKERFILE}" | grep -e "+LABEL version=\".*\"" | awk -F"\"" '{ print $2 }')
+
+  if [ -z "${NEXT_VERSION}" ]; then
+    echo ""
+    echo "ERROR: No version label defined in Dockerfile. You may need to add 'LABEL version' in '${DOCKERFILE}'. Aborting."
+    echo ""
+
+    false
+  fi
+
+  if [ -z "${PREV_VERSION}" ]; then
+    PREV_VERSION=0
+    echo ""
+    echo "WARNING: no previous version found. Will set \$PREV_VERSION = 0."
+    echo ""
+  fi
+
+  if [[ $((PREV_VERSION + 1)) != $((NEXT_VERSION)) ]]; then
+    echo ""
+    echo "ERROR: Version label in Dockerfile was not incremented. You may need to change 'LABEL version' in '${DOCKERFILE}'. Aborting."
+    echo ""
+
+    false
+  fi
+}
+
+build_docker() {
+  echo "-- build_docker"
+
+  docker build "scripts/docker/${IMAGE_NAME}" --file "scripts/docker/${IMAGE_NAME}/Dockerfile.${IMAGE_VARIANT}" --tag "${IMAGE_NAME}"
+}
+
+test_docker() {
+  echo "-- test_docker @ '${PWD}'"
+
+  docker run -v "${PWD}:/root/project" "${IMAGE_NAME}" "/root/project/scripts/ci/docker_test_${IMAGE_VARIANT}.sh"
+}
+
+push_docker() {
+  echo "-- push_docker"
+
+  VERSION=$(docker inspect --format='{{.Config.Labels.version}}' "${IMAGE_NAME}")
+  DOCKER_IMAGE_ID="${DOCKER_REPOSITORY}/${IMAGE_NAME}-${IMAGE_VARIANT}"
+
+  docker tag "${IMAGE_NAME}" "${DOCKER_IMAGE_ID}:${VERSION}"
+  docker push "${DOCKER_IMAGE_ID}:${VERSION}"
+
+  REPO_DIGEST=$(docker inspect --format='{{.RepoDigests}}' "${DOCKER_IMAGE_ID}:${VERSION}")
+
+  docker tag "${IMAGE_NAME}" "${DOCKER_IMAGE_ID}:latest"
+  docker push "${DOCKER_IMAGE_ID}:latest"
+
+  echo "::set-env name=DOCKER_IMAGE::${DOCKER_IMAGE_ID}:${VERSION}"
+  echo "::set-env name=DOCKER_REPO_DIGEST::${REPO_DIGEST}"
+}
+
+check_parameters
+check_version
+build_docker
+test_docker
+push_docker
diff --git a/.circleci/docker/Dockerfile.emscripten b/scripts/docker/buildpack/Dockerfile.emscripten
similarity index 99%
rename from .circleci/docker/Dockerfile.emscripten
rename to scripts/docker/buildpack/Dockerfile.emscripten
index d2456bb2ae0b..4285e0d30d59 100644
--- a/.circleci/docker/Dockerfile.emscripten
+++ b/scripts/docker/buildpack/Dockerfile.emscripten
@@ -29,6 +29,7 @@
 #   make version=1.39.15 build
 #
 FROM emscripten/emsdk:1.39.15 AS base
+LABEL version="1"
 
 ADD emscripten.jam /usr/src
 RUN set -ex; \
diff --git a/.circleci/docker/Dockerfile.ubuntu1604.clang.ossfuzz b/scripts/docker/buildpack/Dockerfile.ubuntu1604.clang.ossfuzz
similarity index 99%
rename from .circleci/docker/Dockerfile.ubuntu1604.clang.ossfuzz
rename to scripts/docker/buildpack/Dockerfile.ubuntu1604.clang.ossfuzz
index f7dfc7001bdf..cb8a5f56d609 100644
--- a/.circleci/docker/Dockerfile.ubuntu1604.clang.ossfuzz
+++ b/scripts/docker/buildpack/Dockerfile.ubuntu1604.clang.ossfuzz
@@ -22,6 +22,7 @@
 # (c) 2016-2019 solidity contributors.
 #------------------------------------------------------------------------------
 FROM gcr.io/oss-fuzz-base/base-clang as base
+LABEL version="1"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
diff --git a/.circleci/docker/Dockerfile.ubuntu1804 b/scripts/docker/buildpack/Dockerfile.ubuntu1804
similarity index 99%
rename from .circleci/docker/Dockerfile.ubuntu1804
rename to scripts/docker/buildpack/Dockerfile.ubuntu1804
index fa651900b873..a50d7c612f50 100644
--- a/.circleci/docker/Dockerfile.ubuntu1804
+++ b/scripts/docker/buildpack/Dockerfile.ubuntu1804
@@ -22,6 +22,7 @@
 # (c) 2016-2019 solidity contributors.
 #------------------------------------------------------------------------------
 FROM buildpack-deps:bionic AS base
+LABEL version="1"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
diff --git a/.circleci/docker/Dockerfile.ubuntu2004 b/scripts/docker/buildpack/Dockerfile.ubuntu2004
similarity index 98%
rename from .circleci/docker/Dockerfile.ubuntu2004
rename to scripts/docker/buildpack/Dockerfile.ubuntu2004
index a021b6533486..f3fa4031dd21 100644
--- a/.circleci/docker/Dockerfile.ubuntu2004
+++ b/scripts/docker/buildpack/Dockerfile.ubuntu2004
@@ -22,6 +22,7 @@
 # (c) 2016-2019 solidity contributors.
 #------------------------------------------------------------------------------
 FROM buildpack-deps:focal AS base
+LABEL version="1"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -58,5 +59,7 @@ RUN set -ex; \
 
 FROM base
 COPY --from=libraries /usr/lib /usr/lib
+RUN true
 COPY --from=libraries /usr/bin /usr/bin
+RUN true
 COPY --from=libraries /usr/include /usr/include
diff --git a/.circleci/docker/Dockerfile.ubuntu2004.clang b/scripts/docker/buildpack/Dockerfile.ubuntu2004.clang
similarity index 98%
rename from .circleci/docker/Dockerfile.ubuntu2004.clang
rename to scripts/docker/buildpack/Dockerfile.ubuntu2004.clang
index c8d057eb11a0..c0d474648068 100644
--- a/.circleci/docker/Dockerfile.ubuntu2004.clang
+++ b/scripts/docker/buildpack/Dockerfile.ubuntu2004.clang
@@ -22,6 +22,7 @@
 # (c) 2016-2019 solidity contributors.
 #------------------------------------------------------------------------------
 FROM buildpack-deps:focal AS base
+LABEL version="1"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -60,5 +61,7 @@ RUN set -ex; \
 
 FROM base
 COPY --from=libraries /usr/lib /usr/lib
+RUN true
 COPY --from=libraries /usr/bin /usr/bin
+RUN true
 COPY --from=libraries /usr/include /usr/include
diff --git a/.circleci/docker/emscripten.jam b/scripts/docker/buildpack/emscripten.jam
similarity index 100%
rename from .circleci/docker/emscripten.jam
rename to scripts/docker/buildpack/emscripten.jam