Check links in mdbook. Also changed image to debian bookworm.

.gitlab-ci.yml

+# # Official language image. Look for the different tagged releases at:
+# # https://hub.docker.com/r/library/rust/tags/
+# image: "rust:1.70-alpine3.17"
+# # Use cargo to test the project
+# before_script:
+#   - apk add --no-cache musl-dev curl
+#   - mkdir -p $HOME/.cargo/bin
+#   - curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.31/mdbook-v0.4.31-x86_64-unknown-linux-musl.tar.gz | tar -xz --directory=$HOME/.cargo/bin
+#   - curl -L https://github.com/Michael-F-Bryan/mdbook-linkcheck/releases/download/v0.7.7/mdbook-linkcheck.x86_64-unknown-linux-gnu.zip -o mdbook-linkcheck.zip
+#   - unzip mdbook-linkcheck.zip -d $HOME/.cargo/bin && chmod +x $HOME/.cargo/bin/mdbook-linkcheck
+#   # - cargo install mdbook-linkcheck
+#   - rustup component add rustfmt
+#   - rustup component add clippy
+#   - export PATH=$PATH:$HOME/.cargo/bin
+#   ##
+#   ## Install ssh-agent if not already installed, it is required by Docker.
+#   ##
+#   - 'which ssh-agent || (apk add --update openssh-client)'
+#   - 'which rsync || (apk add --update rsync)'
+#   - 'which chmod || (apk add --update chmod)'
+#   ##
+#   ## Run ssh-agent (inside the build environment)
+#   ##
+#   - eval $(ssh-agent -s)
+#   ##
+#   ## Give the right permissions, otherwise ssh-add will refuse to add files
+#   ## Add the SSH key stored in SSH_PRIVATE_KEY file type CI/CD variable to the agent store
+#   ##
+#   - echo "$SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null
+#   ##
+#   ## Create the SSH directory and give it the right permissions
+#   ##
+#   - mkdir -p ~/.ssh
+#   - chmod 700 ~/.ssh
+#   ##
+#   ## Assuming you created the SSH_KNOWN_HOSTS file type CI/CD variable, uncomment the
+#   ## following two lines.
+#   ##
+#   - echo "$SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts
+#   - chmod 644 ~/.ssh/known_hosts
+
 # Official language image. Look for the different tagged releases at:
 # https://hub.docker.com/r/library/rust/tags/
-image: "rust:1.70-alpine3.17"
+image: "rust:1-slim-bookworm"
 # Use cargo to test the project
 before_script:
-  - apk add --no-cache musl-dev curl
+  - apt update && apt upgrade -y
+  - apt install curl unzip -y
   - mkdir -p $HOME/.cargo/bin
   - curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.31/mdbook-v0.4.31-x86_64-unknown-linux-musl.tar.gz | tar -xz --directory=$HOME/.cargo/bin
-  - export PATH=$PATH:$HOME/.cargo/bin
+  - curl -L https://github.com/Michael-F-Bryan/mdbook-linkcheck/releases/download/v0.7.7/mdbook-linkcheck.x86_64-unknown-linux-gnu.zip -o mdbook-linkcheck.zip
+  - unzip mdbook-linkcheck.zip -d $HOME/.cargo/bin && chmod +x $HOME/.cargo/bin/mdbook-linkcheck
+  # - cargo install mdbook-linkcheck
   - rustup component add rustfmt
+  - rustup component add clippy
+  - export PATH=$PATH:$HOME/.cargo/bin
   ##
   ## Install ssh-agent if not already installed, it is required by Docker.
   ##
-  - 'which ssh-agent || (apk add --update openssh-client)'
-  - 'which rsync || (apk add --update rsync)'
-  - 'which chmod || (apk add --update chmod)'
+  - 'which ssh-agent || (apt install openssh-client -y)'
+  - 'which rsync || (apt install rsync -y)'
+  - 'which chmod || (apt install chmod -y)'
   ##
   ## Run ssh-agent (inside the build environment)
   ##
@@ -44,6 +90,10 @@ test:cargo:
   stage: test
   script:
     - rustc --version && cargo --version  # Print version info for debugging
+    - cargo clippy --version
+    - rustfmt --version 
+    - ls -ltr $HOME/.cargo/bin
+    - mdbook --version && mdbook-linkcheck --version
 
 build:codes:
   stage: build

book/book.toml

@@ -7,3 +7,16 @@ title = "Rust-101: Université d'été"
 
 [output.html.playground]
 editable = true
+
+[output.linkcheck]
+# Should we check links on the internet? Enabling this option adds a
+# non-negligible performance impact
+follow-web-links = true
+
+# How should warnings be treated?
+#
+# - "warn" will emit warning messages
+# - "error" treats all warnings as errors, failing the linkcheck
+# - "ignore" will ignore warnings, suppressing diagnostic messages and allowing
+#   the linkcheck to continuing
+warning-policy = "error"