Merge bitcoin/bitcoin#33136: ci: Remove redundant RUN_UNIT_TESTS_SEQUENTIAL

fae610d858 ci: Remove redundant RUN_UNIT_TESTS_SEQUENTIAL (MarcoFalke)

Pull request description:

  `RUN_UNIT_TESTS_SEQUENTIAL` is useful to detect cases where global state is left dirty in the test process and leads to subsequent unit test cases failing. However, one CI task is sufficient to catch this.

  As there already is one, add docs there and remove this env var (and extra logic).

ACKs for top commit:
  fanquake:
    ACK fae610d858

Tree-SHA512: b7ace1257d039f144cb0acb08d5d19d641028464517e6a2468e248ed79b2511512dc904867dacd66157b7483ec8041c95cce00f8ce3c89f3a2c3bb47939d7ff9

.github/workflows/ci.yml

@@ -379,7 +379,7 @@ jobs:
       - name: Run unit tests
         # Can't use ctest here like other jobs as we don't have a CMake build tree.
         run: |
-          ./bin/test_bitcoin.exe -l test_suite
+          ./bin/test_bitcoin.exe -l test_suite  # Intentionally run sequentially here, to catch test case failures caused by dirty global state from prior test cases.
           ./src/secp256k1/bin/exhaustive_tests.exe
           ./src/secp256k1/bin/noverify_tests.exe
           ./src/secp256k1/bin/tests.exe

ci/test/00_setup_env_native_previous_releases.sh

@@ -12,8 +12,6 @@ export CI_IMAGE_NAME_TAG="mirror.gcr.io/ubuntu:22.04"
 export PACKAGES="gcc-11 g++-11 python3-zmq"
 export DEP_OPTS="CC=gcc-11 CXX=g++-11"
 export TEST_RUNNER_EXTRA="--previous-releases --coverage --extended --exclude feature_dbcrash"  # Run extended tests so that coverage does not fail, but exclude the very slow dbcrash
-export RUN_UNIT_TESTS_SEQUENTIAL="true"
-export RUN_UNIT_TESTS="false"
 export GOAL="install"
 export CI_LIMIT_STACK_SIZE=1
 export DOWNLOAD_PREVIOUS_RELEASES="true"

ci/test/03_test_script.sh

@@ -74,7 +74,7 @@ if [ "$RUN_FUZZ_TESTS" = "true" ]; then
     echo "Using qa-assets repo from commit ..."
     git log -1
   )
-elif [ "$RUN_UNIT_TESTS" = "true" ] || [ "$RUN_UNIT_TESTS_SEQUENTIAL" = "true" ]; then
+elif [ "$RUN_UNIT_TESTS" = "true" ]; then
   export DIR_UNIT_TEST_DATA=${DIR_QA_ASSETS}/unit_test_data/
   if [ ! -d "$DIR_UNIT_TEST_DATA" ]; then
     mkdir -p "$DIR_UNIT_TEST_DATA"
@@ -176,10 +176,6 @@ if [ "$RUN_UNIT_TESTS" = "true" ]; then
     --timeout $(( TEST_RUNNER_TIMEOUT_FACTOR * 60 ))
 fi
 
-if [ "$RUN_UNIT_TESTS_SEQUENTIAL" = "true" ]; then
-  DIR_UNIT_TEST_DATA="${DIR_UNIT_TEST_DATA}" LD_LIBRARY_PATH="${DEPENDS_DIR}/${HOST}/lib" "${BASE_BUILD_DIR}"/bin/test_bitcoin --catch_system_errors=no -l test_suite
-fi
-
 if [ "$RUN_FUNCTIONAL_TESTS" = "true" ]; then
   # parses TEST_RUNNER_EXTRA as an array which allows for multiple arguments such as TEST_RUNNER_EXTRA='--exclude "rpc_bind.py --ipv6"'
   eval "TEST_RUNNER_EXTRA=($TEST_RUNNER_EXTRA)"