ci: Fix QEMU_USER_CMD parse issues

* Fix bash syntax by adding missing -

* Disable QEMU_USER_CMD fallback when it is set

  Apparently bash can't distinguish an unset variable from a variable
  that is set to the empty string

* Export the environment variable to the docker env, otherwise it
  couldn't be used there

Author: MarcoFalke

ci/test/00_setup_env_arm.sh

@@ -9,7 +9,7 @@ export LC_ALL=C.UTF-8
 export HOST=arm-linux-gnueabihf
 # The host arch is unknown, so we run the tests through qemu.
 # If the host is arm and wants to run the tests natively, it can set QEMU_USER_CMD to the empty string.
-export QEMU_USER_CMD="${QEMU_USER_CMD:"qemu-arm -L /usr/arm-linux-gnueabihf/"}"
+if [ -z ${QEMU_USER_CMD+x} ]; then export QEMU_USER_CMD="${QEMU_USER_CMD:-"qemu-arm -L /usr/arm-linux-gnueabihf/"}"; fi
 # We don't know whether the host can run the cross compiled binaries. To run them, either qemu-user or libc6:armhf for
 # the target is required, so install both.
 export DPKG_ADD_ARCH="armhf"

ci/test/00_setup_env_s390x.sh

@@ -9,7 +9,7 @@ export LC_ALL=C.UTF-8
 export HOST=s390x-linux-gnu
 # The host arch is unknown, so we run the tests through qemu.
 # If the host is s390x and wants to run the tests natively, it can set QEMU_USER_CMD to the empty string.
-export QEMU_USER_CMD="${QEMU_USER_CMD:"qemu-s390x"}"
+if [ -z ${QEMU_USER_CMD+x} ]; then export QEMU_USER_CMD="${QEMU_USER_CMD:-"qemu-s390x"}"; fi
 export PACKAGES="python3-zmq bsdmainutils qemu-user"
 export RUN_UNIT_TESTS=true
 export RUN_FUNCTIONAL_TESTS=true

ci/test/04_install.sh

@@ -41,7 +41,7 @@ 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: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_|CCACHE_|WINEDEBUG|LC_ALL|BOOST_TEST_RANDOM|CONFIG_SHELL|(ASAN|LSAN|TSAN|UBSAN)_OPTIONS)' | tee /tmp/env
+env | grep -E '^(BITCOIN_CONFIG|BASE_|QEMU_|CCACHE_|WINEDEBUG|LC_ALL|BOOST_TEST_RANDOM|CONFIG_SHELL|(ASAN|LSAN|TSAN|UBSAN)_OPTIONS)' | tee /tmp/env
 if [[ $HOST = *-mingw32 ]]; then
   DOCKER_ADMIN="--cap-add SYS_ADMIN"
 elif [[ $BITCOIN_CONFIG = *--with-sanitizers=*address* ]]; then # If ran with (ASan + LSan), Docker needs access to ptrace (https://github.com/google/sanitizers/issues/764)