qa: Create unicode tempdir in test_runner

.travis.yml

@@ -17,6 +17,7 @@ env:
     - RUN_TESTS=false
     - RUN_BENCH=false  # Set to true for any one job that has debug enabled, to quickly check bench is not crashing or hitting assertions
     - DOCKER_NAME_TAG=ubuntu:18.04
+    - LC_ALL=C.UTF-8
     - BOOST_TEST_RANDOM=1$TRAVIS_BUILD_ID
     - CCACHE_SIZE=100M
     - CCACHE_TEMPDIR=/tmp/.ccache-temp
@@ -32,7 +33,7 @@ before_install:
     - END_FOLD () { RET=$?; echo "travis_fold:end:${CURRENT_FOLD_NAME}"; return $RET; }
 install:
     - travis_retry docker pull $DOCKER_NAME_TAG
-    - env | grep -E '^(CCACHE_|WINEDEBUG|BOOST_TEST_RANDOM|CONFIG_SHELL)' | tee /tmp/env
+    - env | grep -E '^(CCACHE_|WINEDEBUG|LC_ALL|BOOST_TEST_RANDOM|CONFIG_SHELL)' | tee /tmp/env
     - if [[ $HOST = *-mingw32 ]]; then DOCKER_ADMIN="--cap-add SYS_ADMIN"; fi
     - DOCKER_ID=$(docker run $DOCKER_ADMIN -idt --mount type=bind,src=$TRAVIS_BUILD_DIR,dst=$TRAVIS_BUILD_DIR --mount type=bind,src=$CCACHE_DIR,dst=$CCACHE_DIR -w $TRAVIS_BUILD_DIR --env-file /tmp/env $DOCKER_NAME_TAG)
     - DOCKER_EXEC () { docker exec $DOCKER_ID bash -c "cd $PWD && $*"; }

test/functional/test_runner.py

@@ -229,7 +229,7 @@ def main():
     logging.basicConfig(format='%(message)s', level=logging_level)
 
     # Create base test directory
-    tmpdir = "%s/bitcoin_test_runner_%s" % (args.tmpdirprefix, datetime.datetime.now().strftime("%Y%m%d_%H%M%S"))
+    tmpdir = "%s/test_runner_₿_🏃_%s" % (args.tmpdirprefix, datetime.datetime.now().strftime("%Y%m%d_%H%M%S"))
     os.makedirs(tmpdir)
 
     logging.debug("Temporary test directory at %s" % tmpdir)