diff --git a/docs/build_integration.md b/docs/build_integration.md
index d95fb59..2257a27 100644
--- a/docs/build_integration.md
+++ b/docs/build_integration.md
@@ -194,6 +194,11 @@ See the [Provided Environment Variables](https://github.com/google/oss-fuzz/blob
 page in OSS-Fuzz's `base-builder` image documentation for more details on
 environment variables that are available to `build.sh`.
 
+If some environment variables needs to be passed from your CI to the build,
+(such as `GOPROXY` for instance), any environment prefixed by `CFL_EXTRA_` can be used.
+The first step is `export CFL_EXTRA_MYENV=$MYENV` in the CI script.
+The second step is `export MYENV=$CFL_EXTRA_MYENV` in build.sh
+
 ## Fuzzer execution environment
 
 You should not make any assumptions on the availability of dependent packages
diff --git a/docs/running-clusterfuzzlite/gitlab.md b/docs/running-clusterfuzzlite/gitlab.md
index 7cc8c26..b804070 100644
--- a/docs/running-clusterfuzzlite/gitlab.md
+++ b/docs/running-clusterfuzzlite/gitlab.md
@@ -189,7 +189,7 @@ clusterfuzzlite-coverage:
   rules:
     - if: $MODE == "coverage"
   before_script:
-    - export CFL_CONTAINER_ID=`cut -c9- < /proc/1/cpuset`
+    - export CFL_CONTAINER_ID=`docker ps -q -f "label=com.gitlab.gitlab-runner.job.id=$CI_JOB_ID" -f "label=com.gitlab.gitlab-runner.type=build"`
   script:
     - python3 "/opt/oss-fuzz/infra/cifuzz/cifuzz_combined_entrypoint.py"
   artifacts: