Compiling sketch: /home/runner/Arduino/libraries/AceTime/examples/HelloDateTime
In file included from /home/runner/.arduino15/packages/arduino/hardware/samd/1.8.11/cores/arduino/api/ArduinoAPI.h:31:0,
/home/runner/.arduino15/packages/arduino/hardware/samd/1.8.11/cores/arduino/api/Print.h:96:16: error: 'Print' is already declared in this scope
Error during build: exit status 1
Error: Compilation failed
I recommend interested parties to read the real issue on GitHub to see the full story:
I suppose that in some cases where discussions were deleted from GitHub, that "gitmemory" website is useful (though of course unfortunate for the people who wanted to remove that content from the Internet for whatever reason), but in this case where the full original discussion is available to the whole world, it's just a content scraper serving random stuff out of context with lots of lovely ads (which GitHub does not have) to make the site owner money.
If you read the discussion on GitHub, you'll see that I did take action on this situation (for anyone who doesn't know, my GitHub user name is the oh so clever "per1234"). However, I did not remove it. The reason is that the purpose of the CI system is to find problems. This is a real problem and the system found it. Even though the failures can cause confusion to contributors, I still think that removing legitimate checks just to get a passing CI run is the wrong approach.
The review of pull requests to the arduino/ArduinoCore-samd repository is done by a human. The automated CI system is only there to facilitate the review. The reviewer is fully able to interpret the CI results and disregard the pre-existing failures that are completely unrelated to the changes proposed in the pull request. So this failure does not in any way block progress on the project development.