Every once in a while I need to verify that Microsoft Git's test suite passes for changes that are not yet meant for public consumption, and since it was (made) too difficult to keep up a working Azure Pipeline definition, I have to use GitHub Actions in a private GitHub repository for that purpose. In these tests, basically all Dockerized CI jobs fail consistently. The symptom is something like: error: cannot create async thread: Resource temporarily unavailable in the middle of a test, typically in the t5xxx-t6xxx range. The first such error is immediately followed by plenty more of these errors, and not a single test succeeds afterwards. At first, I thought that maybe the massive parallelism I enjoy there is the problem, and I thought that the cgroups limits might be shared between the many containers that run on essentially the same physical machine. But even reducing the matrix to just a single of those Dockerized jobs runs into the very same problems. The underlying reason seems to be a substantial difference in the hosted runners that execute these Dockerized jobs: forcing the PID limit of the container to a high number lets the jobs pass, even when running the complete matrix of all 13 Dockerized jobs concurrently. But that's not the only difference: The jobs seem to take a lot longer in these containers than, say, in the containers made available to https://github.com/git/git. When forcing a PID limit of 64k in that private repository, the jobs completed successfully, but they also took a lot longer, between 2x to 2.5x longer, i.e. painfully much longer. Reducing the PID limit to 16k, the CI jobs still passed, but took an equally long amount of time. Reducing the PID limit to 8k caused the errors to reappear. Here are the numbers from three example runs, the first one forcing the PID and nproc limit to 65536, the second one to 16384, the third run is from the public git/git repository: Job | 64k | 16k | reference ------------------------------|---------|---------|--------- almalinux-8 | 19m 3s | 16m 0s | 9m 36s debian-11 | 20m 31s | 20m 3s | 8m 5s fedora-breaking-changes-meson | 16m 29s | 19m 19s | 9m 40s linux-asan-ubsan | 1h 10m | 1h 11m | 34m 36s linux-breaking-changes | 25m 39s | 25m 58s | 13m 15s linux-leaks | 1h 9m | 1h 10m | 33m 30s linux-meson | 28m 9s | 27m 4s | 13m 45s linux-musl-meson | 16m 32s | 13m 39s | 8m 6s linux-reftable-leaks | 1h 13m | 1h 13m | 34m 34s linux-reftable | 26m 2s | 25m 48s | 13m 31s linux-sha256 | 26m 12s | 26m 3s | 12m 36s linux-TEST-vars | 26m 5s | 25m 21s | 13m 25s linux32 | 21m 16s | 19m 57s | 10m 44s It does not look as if the PID limit is the reason for the longer runtime, seeing as the 64k vs 16k timings deviate no more than as is usual with GitHub workflows. So let's go for 16k. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Git for Windows
This is Git for Windows, the Windows port of Git.
The Git for Windows project is run using a governance model. If you encounter problems, you can report them as GitHub issues, discuss them in Git for Windows' Discussions or on the Git mailing list, and contribute bug fixes.
To build Git for Windows, please either install Git for Windows'
SDK, start its git-bash.exe, cd
to your Git worktree and run make, or open the Git worktree as a folder in
Visual Studio.
To verify that your build works, use one of the following methods:
-
If you want to test the built executables within Git for Windows' SDK, prepend
<worktree>/bin-wrappersto thePATH. -
Alternatively, run
make installin the Git worktree. -
If you need to test this in a full installer, run
sdk build git-and-installer. -
You can also "install" Git into an existing portable Git via
make install DESTDIR=<dir>where<dir>refers to the top-level directory of the portable Git. In this instance, you will want to prepend that portable Git's/cmddirectory to thePATH, or test by running that portable Git'sgit-bash.exeorgit-cmd.exe. -
If you built using a recent Visual Studio, you can use the menu item
Build>Install git(you will want to click onProject>CMake Settings for Gitfirst, then click onEdit JSONand then pointinstallRootto themingw64directory of an already-unpacked portable Git).As in the previous bullet point, you will then prepend
/cmdto thePATHor run using the portable Git'sgit-bash.exeorgit-cmd.exe. -
If you want to run the built executables in-place, but in a CMD instead of inside a Bash, you can run a snippet like this in the
git-bash.exewindow where Git was built (ensure that theEOFline has no leading spaces), and then paste into the CMD window what was put in the clipboard:clip.exe <<EOF set GIT_EXEC_PATH=$(cygpath -aw .) set PATH=$(cygpath -awp ".:contrib/scalar:/mingw64/bin:/usr/bin:$PATH") set GIT_TEMPLATE_DIR=$(cygpath -aw templates/blt) set GITPERLLIB=$(cygpath -aw perl/build/lib) EOF -
If you want to run the built executables in-place, but outside of Git for Windows' SDK, and without an option to set/override any environment variables (e.g. in Visual Studio's debugger), you can call the Git executable by its absolute path and use the
--exec-pathoption, like so:C:\git-sdk-64\usr\src\git\git.exe --exec-path=C:\git-sdk-64\usr\src\git helpNote: for this to work, you have to hard-link (or copy) the
.dllfiles from the/mingw64/bindirectory to the Git worktree, or add the/mingw64/bindirectory to thePATHsomehow or other.
To make sure that you are testing the correct binary, call ./git.exe version
in the Git worktree, and then call git version in a directory/window where
you want to test Git, and verify that they refer to the same version (you may
even want to pass the command-line option --build-options to look at the
exact commit from which the Git version was built).
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.adoc to get started, then see
Documentation/giteveryday.adoc for a useful minimum set of commands, and
Documentation/git-<commandname>.adoc for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.adoc
(man gitcvs-migration or git help cvs-migration if git is
installed).
The user discussion and development of core Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email to git+subscribe@vger.kernel.org (see https://subspace.kernel.org/subscribing.html for details). The mailing list archives are available at https://lore.kernel.org/git/, https://marc.info/?l=git and other archival sites. The core git mailing list is plain text (no HTML!).
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks