diff --git a/scripts/dev.sh b/scripts/dev.sh
index e88785f3..6164bcbb 100755
--- a/scripts/dev.sh
+++ b/scripts/dev.sh
@@ -1,10 +1,16 @@
 #!/bin/bash
 set -euo pipefail
 
-# A convenience script that launches a fresh postgres container instance that
-# can be used by the graphql-engine server. After launch the verbose postgres
-# logs will be printed. On shutdown we'll try to clean up the container
-# completely.
+# A development swiss army knife script. The goals are to:
+#
+#  - encode some best practices and hard-won knowledge of quirks and corners of
+#    our tooling
+#  - simplify development; especially for new-comers; instead of writing a huge
+#    document describing how to do various dev tasks (or worse yet, not writing
+#    one), make it runnable
+#
+# This makes use of 'cabal.project.dev-sh*' files when building. See
+# 'cabal.project.dev-sh.local'.
 
 
 echo_pretty() {
@@ -164,24 +170,16 @@ if [ "$MODE" = "graphql-engine" ]; then
   echo_pretty "or press CTRL-C and invoke graphql-engine manually"
   echo_pretty ""
 
-  if [[ ! -e cabal.project.local ]]; then
-    echo_pretty 'No cabal.project.local file exists. Running'
-    echo_pretty '    $ ln -s cabal.project.dev cabal.project.local'
-    echo_pretty 'to use the default.'
-    echo_pretty ''
-    ln -s cabal.project.dev cabal.project.local
-  fi
-
-  RUN_INVOCATION=(cabal new-run --RTS -- exe:graphql-engine +RTS -N -T -RTS
+  RUN_INVOCATION=(cabal new-run --project-file=cabal.project.dev-sh --RTS -- exe:graphql-engine +RTS -N -T -RTS
     --database-url="$DB_URL" serve
     --enable-console --console-assets-dir "$PROJECT_ROOT/console/static/dist")
 
   echo_pretty 'About to do:'
-  echo_pretty '    $ cabal new-build exe:graphql-engine'
+  echo_pretty '    $ cabal new-build --project-file=cabal.project.dev-sh exe:graphql-engine'
   echo_pretty "    $ ${RUN_INVOCATION[*]}"
   echo_pretty ''
 
-  cabal new-build exe:graphql-engine
+  cabal new-build --project-file=cabal.project.dev-sh exe:graphql-engine
   wait_docker_postgres
 
   # Print helpful info after startup logs so it's visible:
@@ -271,8 +269,8 @@ EOL
     echo
 
     if [ ! -z "${GRAPHQL_ENGINE_PID-}" ]; then
-      # This may already have been killed:
-      kill "$GRAPHQL_ENGINE_PID" &>/dev/null || true
+      # Kill the cabal new-run and its children. This may already have been killed:
+      pkill -P "$GRAPHQL_ENGINE_PID" &>/dev/null || true
     fi
 
     case "$MODE" in
@@ -316,30 +314,35 @@ if [ "$MODE" = "postgres" ]; then
   docker logs -f --tail=0 "$PG_CONTAINER_NAME"
 
 elif [ "$MODE" = "test" ]; then
-  #################################
-  ###     Integration tests     ###
-  #################################
+  ########################################
+  ###     Integration / unit tests     ###
+  ########################################
   cd "$PROJECT_ROOT/server"
 
+  # We'll get an hpc error if these exist; they will be deleted below too:
+  rm -f graphql-engine-tests.tix graphql-engine.tix graphql-engine-combined.tix
+
   export EVENT_WEBHOOK_HEADER="MyEnvValue"
   export WEBHOOK_FROM_ENV="http://127.0.0.1:5592"
 
-  # It's better UX to build first (possibly failing) before trying to launch PG:
-  cabal new-build exe:graphql-engine test:graphql-engine-tests
+  # It's better UX to build first (possibly failing) before trying to launch
+  # PG, but make sure that new-run uses the exact same build plan, else we risk
+  # rebuilding twice... ugh
+  cabal new-build --project-file=cabal.project.dev-sh exe:graphql-engine test:graphql-engine-tests
   launch_postgres_container
   wait_docker_postgres
 
   # These also depend on a running DB:
   if [ "$RUN_UNIT_TESTS" = true ]; then
     echo_pretty "Running Haskell test suite"
-    HASURA_GRAPHQL_DATABASE_URL="$DB_URL" cabal new-run -- test:graphql-engine-tests
+    HASURA_GRAPHQL_DATABASE_URL="$DB_URL" cabal new-run --project-file=cabal.project.dev-sh -- test:graphql-engine-tests
   fi
 
   if [ "$RUN_INTEGRATION_TESTS" = true ]; then
     echo_pretty "Starting graphql-engine"
     GRAPHQL_ENGINE_TEST_LOG=/tmp/hasura-dev-test-engine.log
     export HASURA_GRAPHQL_SERVER_PORT=8088
-    cabal new-run -- exe:graphql-engine --database-url="$DB_URL" serve --stringify-numeric-types \
+    cabal new-run --project-file=cabal.project.dev-sh -- exe:graphql-engine --database-url="$DB_URL" serve --stringify-numeric-types \
       --enable-console --console-assets-dir ../console/static/dist \
       &> "$GRAPHQL_ENGINE_TEST_LOG" & GRAPHQL_ENGINE_PID=$!
 
@@ -396,10 +399,50 @@ elif [ "$MODE" = "test" ]; then
     set -u
 
     cd "$PROJECT_ROOT/server"
-    kill -INT "$GRAPHQL_ENGINE_PID"
+    # Kill the cabal new-run and its children. INT so we get hpc report:
+    pkill -INT -P "$GRAPHQL_ENGINE_PID"
     wait "$GRAPHQL_ENGINE_PID" || true
     echo
+  fi  # RUN_INTEGRATION_TESTS
+
+  # TODO generate coverage report when we CTRL-C from 'dev.sh graphql-engine'.
+  # If hpc available, combine any tix from haskell/unit tests:		
+  if command -v hpc >/dev/null; then
+    if [ "$RUN_UNIT_TESTS" = true ] && [ "$RUN_INTEGRATION_TESTS" = true ]; then		
+      # As below, it seems we variously get errors related to having two Main
+      # modules, so exclude:
+      hpc combine --exclude=Main graphql-engine-tests.tix graphql-engine.tix --union > graphql-engine-combined.tix
+    else
+      # One of these should exist
+      cp graphql-engine-tests.tix graphql-engine-combined.tix 2>/dev/null || true
+      cp graphql-engine.tix       graphql-engine-combined.tix 2>/dev/null || true
+    fi
+    # Generate a report including the test code itself (see cabal.project.dev-sh.local):
+    # NOTE: we have to omit the .mix directory for the executable, since it
+    # seems hpc can't cope with two modules of the same name; '--exclude'
+    # didn't help.
+    echo_pretty "Generating code coverage report..."
+    COVERAGE_DIR="dist-newstyle/dev.sh-coverage"
+    hpc markup \
+      --exclude=Main \
+      --hpcdir dist-newstyle/build/*/ghc-*/graphql-engine-*/noopt/hpc/vanilla/mix/graphql-engine-* \
+      --hpcdir dist-newstyle/build/*/ghc-*/graphql-engine-*/t/graphql-engine-tests/noopt/hpc/vanilla/mix/graphql-engine-tests \
+      --reset-hpcdirs graphql-engine-combined.tix \
+      --fun-entry-count \
+      --destdir="$COVERAGE_DIR" >/dev/null
+    hpc report \
+      --exclude=Main \
+      --hpcdir dist-newstyle/build/*/ghc-*/graphql-engine-*/noopt/hpc/vanilla/mix/graphql-engine-* \
+      --hpcdir dist-newstyle/build/*/ghc-*/graphql-engine-*/t/graphql-engine-tests/noopt/hpc/vanilla/mix/graphql-engine-tests \
+      --reset-hpcdirs graphql-engine-combined.tix 
+    echo_pretty "To view full coverage report open:"
+    echo_pretty "  file://$(pwd)/$COVERAGE_DIR/hpc_index.html"
+
+  else
+    echo_warn "Please install hpc to get a combined code coverage report for tests"
   fi
+  rm -f graphql-engine-tests.tix graphql-engine.tix graphql-engine-combined.tix
+
 else
   echo "impossible; fix script."
 fi
diff --git a/server/cabal.project.dev-sh b/server/cabal.project.dev-sh
new file mode 120000
index 00000000..b4c9ceac
--- /dev/null
+++ b/server/cabal.project.dev-sh
@@ -0,0 +1 @@
+cabal.project
\ No newline at end of file
diff --git a/server/cabal.project.dev-sh.freeze b/server/cabal.project.dev-sh.freeze
new file mode 120000
index 00000000..ba0e55e3
--- /dev/null
+++ b/server/cabal.project.dev-sh.freeze
@@ -0,0 +1 @@
+cabal.project.freeze
\ No newline at end of file
diff --git a/server/cabal.project.dev-sh.local b/server/cabal.project.dev-sh.local
new file mode 100644
index 00000000..4b35488a
--- /dev/null
+++ b/server/cabal.project.dev-sh.local
@@ -0,0 +1,23 @@
+-- This is the local cabal configuration file used by the 'scripts/dev.sh'
+-- development script, which uses `... --project-file=cabal.project.dev-sh`
+-- which in turn consults this file.
+--
+-- You can temporarily override values here rather than modifying 'dev.sh'
+-- during development (although that might break certain things)values here 
+-- rather than modifying 'dev.sh' during development (although that might
+-- break certain things).
+
+package *
+  documentation: true
+
+package graphql-engine
+  -- NOTE: this seems to work so long as there is no 'ghc-options: -O2' in the cabal file,
+  -- but new-build will report 'Build profile: -O1' for some reason. 
+  -- See:https://github.com/haskell/cabal/issues/6221 
+  optimization: 0
+  documentation: false
+  flags: +developer
+  -- NOTE: 'cabal new-build --enable-coverage' seems to rebuild all deps with coverage
+  -- which is not what we originally wanted. But building the test modules
+  -- themselves with coverage is actually nice for validation.
+  coverage: true