Welcome to the 83rd edition of Git Rev News, a digest of all things Git. For our goals, the archives, the way we work, and how to contribute or to subscribe, see the Git Rev News page on git.github.io.

This edition covers what happened during the month of December 2021.

• Custom subcommand help handlers

  Sean Allred wrote to the mailing list saying that in his company he is distributing a Git subcommand he named git-foo, which can display its own help, but he was struggling to make this work.

  Running git foo --help doesn't pass --help to git-foo, but instead it is rewritten internally in Git to git help foo, which tries to find and then display a help page for git-foo. This could have worked if Sean could install such a page for git-foo along with the help pages for regular Git commands.

  On Windows, though, by default help pages are displayed in HTML format instead of the 'man' or 'info' formats, and these pages are expected to be in a Git for Windows controlled installation directory that he'd rather not touch.

  One solution he suggested would be to not rewrite git foo --help to git help foo if the foo command is not a builtin.

  Ævar Arnfjörð Bjarmason replied to this suggestion that this might not please everyone, as git send-email --help and git annex --help were currently expected to show the manual, even though these commands are not builtins.

  Dscho, alias Johannes Schindelin, also replied to Sean saying that just looking whether the command is a builtin or not might not be enough, as Git also installs scripts or executables, and provided some example code implementing an is_in_git_exec_path() function.

  Ævar and Dscho then discussed a bit if such a function was needed as Ævar pointed that we already have a way to dump builtins, other known commands and commands unknown to Git, using respectively:

  • git --list-cmds=builtins
  • git --list-cmds=main
  • git --list-cmds=others

  Meanwhile Erik Cervin Edin replied to Ævar's initial reply to Sean saying that when a Git alias is configured for foo and it's used with --help, the user is told that foo is an alias for another command, and the help page for the other command is displayed. So he suggested doing something similar for non-builtin commands that are missing help pages.

  Erik also mentioned that using git-foo --help directly or git foo -h, instead of git foo --help, would allow git-foo to handle everything.

  brian m. carlson replied to Erik that for man pages it might not be possible to distinguish a missing page from another error. He then wondered if there is a similar environment variable as MANPATH for HTML pages, as MANPATH on Unix systems instructs man to search for pages in the directories specified in this variable. He also suggested installing the HTML documentation alongside Git's, as it's expected on Unix systems to have all man pages installed into the same place.

  Junio Hamano, the Git maintainer, then agreed to this suggestion.

  Erik replied to brian and Junio that there was no standard or convention around HTML documentation, and talked about the help.htmlPath configuration variable that could be used to tell Git where to look for HTML pages. He also suggested falling back to searching a missing HTML page starting at the path of the command.

  The discussion continued for some time between Erik, Junio, Philip Oakley and Dscho, especially around the topic of aliases.

  Then Junio spotted the GIT_HTML_PATH environment variable in the code, and noticed that it can currently be used to specify just one directory for HTML pages, while MANPATH can be a colon-separated list of directories. So he suggested changing the code to allow GIT_HTML_PATH to also be a colon-separated list of directories. This would allow people to install HTML pages in directories without the need of administrator rights.

  It looks like no one has yet started working on this though.

• Git 2.35.0, 2.35.0-rc2, 2.35.0-rc1, 2.35.0-rc0
• Git for Windows 2.35.0(1), 2.35.0-rc2(1), 2.35.0-rc1(1), 2.35.0-rc0(1)
• GitLab 14.7 14.6.3, 14.6.2, 14.5.3, and 14.4.5, 14.6.1
• GitHub Enterprise 3.3.2, 3.2.7, 3.1.15, 3.0.23

Various

• Highlights from Git 2.35 by Taylor Blau on GitHub Blog.
• Linux Foundation launches Open Source Software Development, Linux, and Git certification, and three new training courses on the edX platform (including Git for Distributed Software Development (LFD109x)).
• Introducing new Git features to Visual Studio 2022 by Taysser Gherfal on Microsoft Visual Studio DevBlog.

Light reading

• Signing Git Commits with SSH Keys by Danilo Bargen (available since Git version 2.34).
• Git Overview - Computerphile, a video by dr Max Wilson, filmed and edited by Sean Riley.
• Awesome Git Aliases and More Awesome Git Aliases by Landon Schropp on Dawid Walsh Blog.
• Git Organized: A Better Git Flow by Annie Sexton on Render.com Blog; though a better solution would be to use interactive rebase, as described in comments for this article on DEV.to.
• No code reviews by default (to move faster) by Thomas Paul Mann of Raycast (and how it works for them).
• How to Make a Component That Supports Multiple Frameworks in a Monorepo by Rob Levin on CSS-Tricks.
• How Git Works Under the Hood by Faisal Albasu on freeCodeCamp.
• Advanced Git Concepts You Should Know by Tapajyoti Bose on The Practical Dev (also known as DEV.to).
• How to Write Better Git Commit Messages – A Step-By-Step Guide by Natalie Pina on freeCodeCamp; this article talks also about the Conventional Commits specification, first mentioned in Git Rev News Edition #52.
• How to check commit message and branch name with git hooks without any new installation, a short article by Anibal on DEV.to.
• How Bad Can It Git? Characterizing Secret Leakage in Public GitHub Repositories by Michael Meli, Matthew R. McNiece, Bradley Reaves in NDSS 2019; via the morning paper article by Adrian Colyer.
• The Pull Request Paradox: Merge Faster by Promoting Your PR Adding more context to our Pull Requests got them merged two days faster. Here's how it works. By Dan Lines.
• What's in a Good Error Message? Some thoughts on ensuring error messages are useful to the reader. By Gunnar Morling.
• Let's Talk about Error Messages More thoughts on error messages, by Brien King.

Git tools and sites

• git-perl-critic - Command-line interface for the Perl Git::Critic module, reporting Perl::Critic failures (that is, code violating Perl best practices) only on lines changed in the current Git branch. By Curtis "Ovid" Poe.
• Dura is a background process that watches your Git repositories and commits your uncommitted changes without impacting HEAD, the current branch, or the Git index (staged files). With this tool you should not ever lose your work if you're using Git. Written in Rust by Tim Kellogg.
• ResumableGitClone (2017) is a Bash shell script to clone a large repo without retrying again and again, by using a deepening shallow clone.
• git-pull-run is an npm package which automatically runs commands like npm install when fetching changes from Git, but only if certain files have changed. Extended version of the script presented in Automatically Install NPM Dependencies on Git Pull.
• Husky.Net is a Git hooks manager for .NET, among others making it possible to run linters against staged Git files. Inspired by husky, lint-staged, a few other tools, and by Using C# code in your git hooks article by Max Hamulyák (2019).
  • lint-staged was first mentioned in Git Rev News #45
  • husky was first mentioned in Git Rev News #63

This edition of Git Rev News was curated by Christian Couder <christian.couder@gmail.com>, Jakub Narębski <jnareb@gmail.com>, Markus Jansen <mja@jansen-preisler.de> and Kaartic Sivaraam <kaartic.sivaraam@gmail.com> with help from Philip Oakley.