The final LaTeX pre-release for 2021-11-15 is available for testing

A few days ago we submitted the final pre-release of the LaTeX format to CTAN and by now it should be available to all users using MiKTeX or TeX Live (on any operating system).

Main features included in the final pre-release for 2021-11-15

The upcoming release does not contain any major new modules, but is focused around consolidation and improvements of functionality introduced in previous releases. There have been some improvements of the hook management as a result of feedback from developers and our own experience applying the new functionality. This includes one breaking change in behavior (relevant only to package developers), for which we offer compatibility code for now. Thus nothing will break right now, but going forward the new method needs to be used, because at some point in the future the compatibility code will be taken out.

The hook management improvements are

• Standardizing generic hook names;
• Rationalizing the behavior of \RemoveFromHook;
• Providing \ActivateGenericHook;
• Providing a command to clear “next” hook code before invocation;
• Properly clean up after a one-time hook.

Other notable improvements include

• Extending \ShowCommand to show commands defined with \NewDocumentCommand and friends;
• Extending \NewCommandCopy as well, to safely copy such commands to new names;
• Improving the math font family allocation to avoid running out of available math groups in complex documents. A number of math alphabets (controlled through the counter localmathalphabets) are now locally allocated and their math groups can be reused with different alphabets per formula;
• Adding \PackageNote and \PackageNoteOnLine to show notes that aren’t “warnings” on the terminal;
• Supporting an alt key with \includegraphics (anticipating future development);
• Providing a new \newcolumn command and an optional argument to \columnbreak for multicol;
• Altering the default for \tracinglostchars.

There are also a number of smaller enhancements and some bug fixes as usual. The details are discussed in the draft publication of “LaTeX2e News Issue 34”. A full list is given in the changes.txt files that are part of the distribution.

Outlook

We expect to ship the final release (with the same code base as this pre-release) as planned around mid November.

Please help with the testing

We are issuing this final pre-release now in the hope that you will help us by making sure that all the enhancements and fixes we have provided are safe and that they do not have any undesired side effects, so please help with the testing if you can.

This development format allows you to test the upcoming LaTeX release scheduled for 2021-11-15 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problems beforehand but such an undertaking is necessarily incomplete, which is why we are asking for user testing.

Besides developers, we also ask ordinary users to try out the new release, because the more people that test the new format, the higher the chances that any hidden problems are identified before the final release hits the streets.

Processing your documents with the pre-release is straightforward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run

pdflatex-dev myfile    or    lualatex-dev myfile    or    xelatex-dev myfile

instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straightforward.

Enjoy — Frank