diff --git a/ci/README.md b/ci/README.md
index de798607df9..d014565f447 100644
--- a/ci/README.md
+++ b/ci/README.md
@@ -14,10 +14,10 @@ testing compared to other parts of the codebase. If you want to keep the work tr
 system in a virtual machine with a Linux operating system of your choice.
 
 To allow for a wide range of tested environments, but also ensure reproducibility to some extent, the test stage
-requires `docker` to be installed. To install all requirements on Ubuntu, run
+requires `bash`, `docker`, and `python3` to be installed. To install all requirements on Ubuntu, run
 
 ```
-sudo apt install docker.io bash
+sudo apt install bash docker.io python3
 ```
 
 To run the default test stage,
diff --git a/ci/test/04_install.sh b/ci/test/04_install.sh
index 1024222e96a..6390667394f 100755
--- a/ci/test/04_install.sh
+++ b/ci/test/04_install.sh
@@ -18,7 +18,6 @@ export ASAN_OPTIONS="detect_stack_use_after_return=1:check_initialization_order=
 export LSAN_OPTIONS="suppressions=${BASE_ROOT_DIR}/test/sanitizer_suppressions/lsan"
 export TSAN_OPTIONS="suppressions=${BASE_ROOT_DIR}/test/sanitizer_suppressions/tsan:halt_on_error=1:log_path=${BASE_SCRATCH_DIR}/sanitizer-output/tsan"
 export UBSAN_OPTIONS="suppressions=${BASE_ROOT_DIR}/test/sanitizer_suppressions/ubsan:print_stacktrace=1:halt_on_error=1:report_error_type=1"
-env | grep -E '^(BITCOIN_CONFIG|BASE_|QEMU_|CCACHE_|LC_ALL|BOOST_TEST_RANDOM|DEBIAN_FRONTEND|CONFIG_SHELL|(ASAN|LSAN|TSAN|UBSAN)_OPTIONS|PREVIOUS_RELEASES_DIR)' | tee /tmp/env
 if [[ $BITCOIN_CONFIG = *--with-sanitizers=*address* ]]; then # If ran with (ASan + LSan), Docker needs access to ptrace (https://github.com/google/sanitizers/issues/764)
   CI_CONTAINER_CAP="--cap-add SYS_PTRACE"
 fi
@@ -27,6 +26,9 @@ export P_CI_DIR="$PWD"
 export BINS_SCRATCH_DIR="${BASE_SCRATCH_DIR}/bins/"
 
 if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then
+  # Export all env vars to avoid missing some.
+  # Though, exclude those with newlines to avoid parsing problems.
+  python3 -c 'import os; [print(f"{key}={value}") for key, value in os.environ.items() if "\n" not in value]' | tee /tmp/env
   echo "Creating $CI_IMAGE_NAME_TAG container to run in"
   DOCKER_BUILDKIT=1 ${CI_RETRY_EXE} docker build \
       --file "${BASE_ROOT_DIR}/ci/test_imagefile" \