Set the locale in Docker so Python's default output encoding is utf-8

1 files changed, 13 insertions, 15 deletions

diff --git a/dev/ci/docker/README.md b/dev/ci/docker/README.md
index 16c4ac37d9..ed51c8afd3 100644
--- a/dev/ci/docker/README.md
+++ b/dev/ci/docker/README.md
@@ -4,31 +4,29 @@ This directory provides Docker images to be used by Coq's CI. The
 images do support Docker autobuild on `hub.docker.com` and Gitlab's
 private registry.
 
-The Gitlab CI will build a docker image unless the CI environment variable
+The Gitlab CI will build a Docker image unless the CI environment variable
 `SKIP_DOCKER` is set to `true`. This image will be
 stored in the [Gitlab container registry](https://gitlab.com/coq/coq/container_registry)
 under the name given by the `CACHEKEY` variable from
 the [Gitlab CI configuration file](../../../.gitlab-ci.yml).
 
-In Coq's default CI, `SKIP_DOCKER` is set so as to avoid running a lengthy redundant job.
+`SKIP_DOCKER` is set to "true" in `https://gitlab.com/coq/coq` to avoid running
+a lengthy redundant job.  For efficiency, users should enable that setting
+in forked repositories after the initial Docker build in the fork succeeds.
 
-It can be used to regenerate a fresh Docker image on Gitlab through the following steps.
-- Change the `CACHEKEY` variable to a fresh name in the CI configuration in a new commit.
-- Push this commit to a Github PR. This will trigger a Gitlab CI run that will
-  immediately fail, as the Docker image is missing and the `SKIP_DOCKER`
+The steps to generate a new Docker image are:
+- Update the `CACHEKEY` variable in .gitlab-ci.yml with the date and md5.
+- Submit the change in a PR. This triggers a Gitlab CI run that
+  immediately fails, as the Docker image is missing and the `SKIP_DOCKER`
   default value prevents rebuilding the image.
-- Run a new pipeline on Gitlab with that PR branch, using the green "Run pipeline"
-  button on the [web interface](https://gitlab.com/coq/coq/pipelines),
-  with the `SKIP_DOCKER` environment variable set to `false`. This will run a `docker-boot` process, and
-  once completed, a new Docker image will be available in the container registry,
-  with the name set in `CACHEKEY`.
+- Run a new pipeline on Gitlab with that PR branch (e.g. "pr-99999"), using the green
+  "Run pipeline" button on the [web interface](https://gitlab.com/coq/coq/pipelines),
+  with the `SKIP_DOCKER` environment variable set to `false`. This will run a
+  `docker-boot` process, and once completed, a new Docker image will be available in
+  the container registry, with the name set in `CACHEKEY`.
 - Any pipeline with the same `CACHEKEY` will now automatically reuse that
   image without rebuilding it from scratch.
 
-For documentation purposes, we also require keeping in sync the `CACHEKEY` comment
-from the first line of the [Dockerfile](bionic_coq/Dockerfile) in the same
-commit.
-
 In case you do not have the rights to run Gitlab CI pipelines, you should ask
 the ci-maintainers Github team to do it for you.