WIP: Retry link checking

.github/workflows/checks.yml

@@ -36,3 +36,15 @@ jobs:
 
       - name: Check include guards
         run: ./bin/check-include-guards ./exercises/concept ./exercises/practice
+
+      - name: Check links
+        uses: lycheeverse/lychee-action@885c65f3dc543b57c898c8099f4e08c8afd178a2
+        id: lychee
+        with:
+          args: >- 
+            --cache --max-retries 3 --retry-wait-time 5 --max-concurrency 30 --exclude "stackoverflow\.com.*" "gnu\.org.*" 
+            --require-https --insecure --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36" 
+            --no-progress **/*.md **/*.html
+          fail: true
+          token: ${{ secrets.GITHUB_TOKEN }}
+

docs/CONTRIBUTING.md

@@ -201,9 +201,9 @@ Read more about [test runners].
 [clang-format]: https://releases.llvm.org/10.0.0/tools/clang/docs/ClangFormat.html
 [Homebrew]: https://brew.sh
 [implement-an-exercise-from-specification]: https://github.com/exercism/docs/blob/main/building/tracks/practice-exercises/add.md
-[Unity]: http://www.throwtheswitch.org/unity/
-[ThrowTheSwitch]: http://www.throwtheswitch.org/#intro-1-section
-[getting started with unity]: http://www.throwtheswitch.org/getting-started-with-unity/
+[Unity]: https://www.throwtheswitch.org/unity/
+[ThrowTheSwitch]: https://www.throwtheswitch.org/#intro-1-section
+[getting started with unity]: https://www.throwtheswitch.org/getting-started-with-unity/
 [versions]: ./VERSIONS.md
 [test-file-layout]: ./C_STYLE_GUIDE.md#test-file-layout
 [include guards]: https://en.wikipedia.org/wiki/Include_guard

docs/INSTALLATION.md

@@ -28,4 +28,4 @@ If you are using an earlier version of Windows or WSL Bash is not available to y
 [Homebrew]: https://brew.sh
 [Windows Subsystem for Linux]: https://docs.microsoft.com/en-gb/windows/wsl/about
 [MSYS]: https://www.msys2.org
-[mingw-w64]: http://mingw-w64.org
+[mingw-w64]: https://mingw-w64.org

docs/LEARNING.md

@@ -28,7 +28,7 @@ These resources cover [Unity][] and [CppUTest][]; this track uses Unity.
 [Learn C]: https://www.learn-c.org/
 [CS50x]: https://www.edx.org/course/cs50s-introduction-to-computer-science
 [CodeChef]: https://www.codechef.com/ide
-[test-frameworks]: https://www.drdobbs.com/testing/unit-testing-in-c-tools-and-conventions/240156344
+[test-frameworks]: https://web.archive.org/web/20190726064009/https://www.drdobbs.com/testing/unit-testing-in-c-tools-and-conventions/240156344
 [tdd]: https://pragprog.com/titles/jgade/test-driven-development-for-embedded-c
 [Unity]: https://www.throwtheswitch.org/unity/
 [CppUTest]: https://cpputest.github.io/

exercises/shared/.docs/help.md

@@ -13,7 +13,7 @@ To get help if having trouble, you can use the following resources:
 - [The C Programming][K&R] book by K&R is the original source of the language and is still useful today.
 
 [c-track]: https://exercism.org/docs/tracks/c
-[stackoverflow]: http://stackoverflow.com/questions/tagged/c
+[stackoverflow]: https://stackoverflow.com/questions/tagged/c
 [cppreference]: https://en.cppreference.com/w/c
 [tutorialspoint]: https://www.tutorialspoint.com/cprogramming/
 [K&R]: https://www.amazon.com/Programming-Language-2nd-Brian-Kernighan/dp/0131103628/

reference/implementing-a-concept-exercise.md

@@ -78,6 +78,6 @@ If you have any questions regarding implementing the exercise, please post them
 [docs-rationale-for-v3]: https://github.com/exercism/v3/blob/main/docs/rationale-for-v3.md
 [docs-features-of-v3]: https://github.com/exercism/v3/blob/main/docs/features-of-v3.md
 [anatomy-of-a-concept-exercise]: https://www.youtube.com/watch?v=gkbBqd7hPrA
-[unity]: http://www.throwtheswitch.org/unity
+[unity]: https://www.throwtheswitch.org/unity
 [how-to-implement-a-concept-exercise]: https://github.com/exercism/v3/blob/main/docs/maintainers/generic-how-to-implement-a-concept-exercise.md
 [reference]: https://github.com/exercism/v3/blob/main/reference