safe.directory

Symptoms

fatal: detected dubious ownership in repository at
fatal: unsafe repository ('/builds/rPrca3qv/0/group/project' is owned by someone else)
To add an exception for this directory, call:
	git config --global --add safe.directory /builds/rPrca3qv/0/group/project

Source of problem

Current user is not owner of git repository directory (.git).

Workaround

Silence all warning (risky!):

git config --global --add safe.directory '*'

NOTE: * is not glob pattern. It is only special value which turns off warning for all dirs. (The command doesn't interpret the wildcard * as an operator)

.gitconfig
[safe]
    directory=*

Silence warning for specified directory:

git config --global --add safe.directory /home/john/project

NOTE1: Multiple config entries can be addedd to add more directories

NOTE2: safe.directory points only to one specified directory. It doesn't propagate to subdirectories.

Workaround using env

Do not use envirnonment GIT_CONFIG_PARAMETERS. It is only for internal git use, and format is not published.

For modern git (v2.31.0) it is possible to use new env config syntax:

GIT_CONFIG_COUNT=1
GIT_CONFIG_KEY_0=safe.directory
GIT_CONFIG_VALUE_0=*

See: GIT_CONFIG_VALUE_

GIT version changelog:

2.31.0: 
      Two new ways to feed configuration variable-value pairs via
      environment variables have been introduced, and the way
      GIT_CONFIG_PARAMETERS encodes variable/value pairs has been tweaked
      to make it more robust.

Related GIT commit:

f9dbb64fadf599c588a39d2251bb3f9a2f7d572a  2021-01-12 13:27 +0100 Jeff King config: parse more robust format in GIT_CONFIG_PARAMETERS

Workaround for WSL

git config --global --add safe.directory '%(prefix)///wsl$/Ubuntu-22.04/home/username/code/my-repo-name'

Workaround for Yocto

Fix in Poky: bitbake.conf: mark all directories as safe for git to read

This variable can be added to local.conf, but it invalidates whole sstate. Simple solution is to fix one recipe:

do_compile_prepend() {
    git config --global --add safe.directory ${S}
}

Workaround for Gitlab CI

git config --global --add safe.directory ${CI_PROJECT_DIR}
 
# and if needed, for some submodules
git config --global --add safe.directory ${CI_PROJECT_DIR}/bootloader

Workarounds:

Best workaround: https://gitlab.com/gitlab-org/gitlab-runner/-/issues/29022#note_1356788508

config.toml
[[runners]]
  environment = ["GIT_CONFIG_COUNT=1", "GIT_CONFIG_KEY_0=safe.directory", "GIT_CONFIG_VALUE_0=*", "GIT_CONFIG_PARAMETERS='safe.directory=*'"]

or re-register runner with args:

gitlab-runner register \
      --env "GIT_CONFIG_COUNT=1" \
      --env "GIT_CONFIG_KEY_0=safe.directory" \
      --env "GIT_CONFIG_VALUE_0=*" \
      --env "GIT_CONFIG_PARAMETERS="'safe.directory=*'"

Note: According to bitbake.conf: mark all directories as safe for git to read :

This can be set globally via the
internal environment variable GIT_CONFIG_PARAMETERS, we can't use
GIT_CONFIG_*_KEY/VALUE as that isn't present in all the releases which
have the ownership check.