reverting to 4 threads and log compression

.gitlab-ci.yml

@@ -7,7 +7,7 @@ build:
   stage: build
   tags:
     - corsika
-    
+
   # detect_leaks=0 because leak detection doesn't work in CI, but you can
   # try to test with leak detection locally, just set detect_leaks=1
   script:
@@ -17,11 +17,14 @@ build:
     - cmake --build . -- -j4
     - UBSAN_OPTIONS=print_stacktrace=1
       LSAN_OPTIONS=log_threads=1
-      ASAN_OPTIONS=detect_leaks=0:detect_stack_use_after_return=1 ctest -V -O test.txt
+      ASAN_OPTIONS=detect_leaks=0:detect_stack_use_after_return=1 ctest -j4 -V -O test.log
+  after_script:
+    - cd build
+    - gzip -v -9 -S .gz test.log
   artifacts:
     expire_in: 1 week
     paths:
-      - build/test.txt
+      - build/test.log.gz
     when: on_failure
     reports:
       junit: