Rust: tweak qltest logs

* verbosity is raised to DEBUG to have more information in the logs
* color codes are now skipped in the `qltest.log` file
* they are still printed out on the console when running with
  `--show-extractor-output`.

rust/tools/qltest.sh

@@ -1,10 +1,21 @@
 #!/bin/bash
 
 set -eu
+set -o pipefail
 
 export RUST_BACKTRACE=full
 QLTEST_LOG="$CODEQL_EXTRACTOR_RUST_LOG_DIR"/qltest.log
-if ! "$CODEQL_EXTRACTOR_RUST_ROOT/tools/$CODEQL_PLATFORM/extractor" --qltest >> "$QLTEST_LOG" 2>&1; then
-  cat "$QLTEST_LOG"
+TMP_OUT="$(mktemp)"
+trap 'rm -f "$TMP_OUT"' EXIT
+# put full-color output on the side, but remove the color codes from the log file
+# also, print (colored) output only in case of failure
+if ! "$CODEQL_EXTRACTOR_RUST_ROOT/tools/$CODEQL_PLATFORM/extractor" \
+     --qltest \
+     --logging-verbosity=progress+ \
+     2>&1 \
+     | tee "$TMP_OUT" \
+     | sed 's/\x1B\[[0-9;]\{1,\}[A-Za-z]//g' \
+     > "$QLTEST_LOG"; then
+  cat "$TMP_OUT"
   exit 1
 fi