diff --git a/.github/workflows/build-larch.yml b/.github/workflows/build-larch.yml
new file mode 100644
index 00000000..0c4dfea8
--- /dev/null
+++ b/.github/workflows/build-larch.yml
@@ -0,0 +1,45 @@
+name: Build and run tests
+on:
+  workflow_dispatch:
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: Prepare build environment
+        run: |
+          sudo apt-get update
+          sudo apt-get install build-essential cmake zlib1g-dev python3-pip python3-pytest
+      - name: Install conda
+        run: |
+          curl -L https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh > Miniconda3-latest-Linux-x86_64.sh
+          bash Miniconda3-latest-Linux-x86_64.sh -b -p ~/miniconda
+          ~/miniconda/bin/conda update -n base -c defaults conda
+      - name: Create conda env
+        run: |
+          source ~/miniconda/etc/profile.d/conda.sh
+          conda env create -f environment.yml
+      - name: Build (cmake step)
+        run: |
+          source ~/miniconda/etc/profile.d/conda.sh
+          conda activate larch-dev
+          mkdir build
+          cd build
+          export CMAKE_NUM_THREADS="8"
+          cmake -DCMAKE_BUILD_TYPE=Debug ..
+      - name: Build (make step)
+        run: |
+          source ~/miniconda/etc/profile.d/conda.sh
+          conda activate larch-dev
+          cd build
+          make -j20
+          ln -s ../data
+      - name: Run tests
+        run: |
+          source ~/miniconda/etc/profile.d/conda.sh
+          conda activate larch-dev
+          cd build
+          ./larch-test -tag slow
diff --git a/README.md b/README.md
index 84a314b3..2ede660e 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,8 @@ file provided:
 Building
 --------
 
+- Note: If you run against memory limitations during the cmake step, you can regulate number of parallel threads with `export CMAKE_NUM_THREADS="8"` (reduce number as necessary).
+
 `git submodule update --init --recursive`
 `mkdir build`
 `cd build`
diff --git a/protobuf.cmake b/protobuf.cmake
index fe9e723e..1f4c7ef5 100644
--- a/protobuf.cmake
+++ b/protobuf.cmake
@@ -3,6 +3,10 @@ include(FetchContent)
 set(Protobuf_USE_STATIC_LIBS ON)
 cmake_policy(SET CMP0026 OLD)
 
+if(NOT DEFINED CMAKE_NUM_THREADS)
+  set(CMAKE_NUM_THREADS "16")
+endif()
+
 FetchContent_Declare(
   protocolbuffers_protobuf
   GIT_REPOSITORY https://github.com/protocolbuffers/protobuf.git
@@ -19,33 +23,36 @@ set(Protobuf_ROOT ${protocolbuffers_protobuf_SOURCE_DIR})
 message(STATUS "Setting up protobuf ...")
 execute_process(
   COMMAND
-    ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -D protobuf_BUILD_TESTS=OFF -D protobuf_BUILD_PROTOC_BINARIES=ON -D CMAKE_POSITION_INDEPENDENT_CODE=ON -G "${CMAKE_GENERATOR}" .
+  ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -D protobuf_BUILD_TESTS=OFF -D protobuf_BUILD_PROTOC_BINARIES=ON -D CMAKE_POSITION_INDEPENDENT_CODE=ON -G "${CMAKE_GENERATOR}" .
   RESULT_VARIABLE result
   WORKING_DIRECTORY ${Protobuf_ROOT})
+
 if(result)
   message(FATAL_ERROR "Failed to download protobuf (${result})!")
 endif()
 
 message(STATUS "Building protobuf ...")
 execute_process(
-  COMMAND ${CMAKE_COMMAND} --build . --parallel
+  COMMAND ${CMAKE_COMMAND} --build . --parallel ${CMAKE_NUM_THREADS}
   RESULT_VARIABLE result
   WORKING_DIRECTORY ${Protobuf_ROOT})
+
 if(result)
   message(FATAL_ERROR "Failed to build protobuf (${result})!")
 endif()
 
 message(STATUS "Installing protobuf ...")
 execute_process(
-    COMMAND ${CMAKE_COMMAND} --install . --config ${CMAKE_BUILD_TYPE} --prefix ${Protobuf_ROOT}/install
-RESULT_VARIABLE result
-WORKING_DIRECTORY ${Protobuf_ROOT})
+  COMMAND ${CMAKE_COMMAND} --install . --config ${CMAKE_BUILD_TYPE} --prefix ${Protobuf_ROOT}/install
+  RESULT_VARIABLE result
+  WORKING_DIRECTORY ${Protobuf_ROOT})
+
 if(result)
-    message(FATAL_ERROR "Failed to build protobuf (${result})!")
+  message(FATAL_ERROR "Failed to build protobuf (${result})!")
 endif()
 
-if (NOT EXISTS ${Protobuf_ROOT}/install/lib64)
-  file (CREATE_LINK ${Protobuf_ROOT}/install/lib ${Protobuf_ROOT}/install/lib64 SYMBOLIC)
+if(NOT EXISTS ${Protobuf_ROOT}/install/lib64)
+  file(CREATE_LINK ${Protobuf_ROOT}/install/lib ${Protobuf_ROOT}/install/lib64 SYMBOLIC)
 endif()
 
 find_package(Protobuf CONFIG REQUIRED HINTS ${Protobuf_ROOT}/install/lib64/cmake)
@@ -67,7 +74,7 @@ if(Protobuf_FOUND)
 else()
   message(
     FATAL_ERROR
-      "Protobuf package not found -> specify search path via Protobuf_ROOT variable"
+    "Protobuf package not found -> specify search path via Protobuf_ROOT variable"
   )
 endif()