On 4/27/2019 9:43 AM, SZEDER Gábor wrote:
On Mon, Apr 15, 2019 at 01:39:47PM -0700, Jeff Hostetler via GitGitGadget wrote:
From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Teach git to read the system and global config files for
default Trace2 settings. This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.
The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.
Only the system and global config files are used. Repo and worktree
local config files are ignored. Likewise, the "-c" command line
arguments are also ignored. These limits are for performance reasons.
(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled. In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.
(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).
Reading the configuration that early causes unexpected and undesired
behavior change:
$ sudo chmod a-rwx /usr/local/etc/gitconfig
$ ./BUILDS/v2.21.0/bin/git
usage: git [--version] [--help] [-C <path>] [-c <name>=<value>]
<... snip rest of usage ...>
$ strace ./BUILDS/v2.21.0/bin/git 2>&1 |grep config -c
0
$ ./git
fatal: unable to access '/usr/local/etc/gitconfig': Permission denied
$ ./git --version
fatal: unable to access '/usr/local/etc/gitconfig': Permission denied
I think at least 'git', 'git --help', and 'git --version' should Just
Work, no matter what.
This breaks the 32 bit Linux build job on Travis CI, because:
- In the 32 bit Docker image we change UID from root to regular user
while preserving the environment, including $HOME.
- Since $HOME is the default build prefix, Git will look for the
system-wide configuration under '/root/etc/gitconfig', which fails
as a regular user.
- Our test harness checks early (i.e. earlier than setting
GIT_CONFIG_NOSYSTEM=1) whether Git has been built successfully by
attempting to run '$GIT_BUILD_DIR}/git', which fails because of
the inaccessible system-wide config file, and in turn the harness
assumes that Git hasn't been built and aborts.
https://travis-ci.org/git/git/jobs/524403682#L1258
It appears that config.c:do_git_config_sequence() passes flags = 0
to access_or_die() rather than ACCESS_EACCES_OK as it does for the
other scopes. This causes the fatal error, rather than ignoring the
problem.
Reasons for this were discussed in:
4698c8feb1 config: allow inaccessible configuration under $HOME
I'll push a fix shortly.
Thanks
Jeff
