Git 的一些环境变量
参考：https://git-scm.com/book/zh/v2/Git-%E5%86%85%E9%83%A8%E5%8E%9F%E7%90%86-%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F 和 https://git-scm.com/docs/git#_environment_variables 。
GIT_TRACE GIT_TRACE=1 可以显示具体的git内部执行过程，比如：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 $ GIT_TRACE=1 git pull 10:15:16.423653 git.c:344 trace: built-in: git pull 10:15:16.424388 run-command.c:646 trace: run_command: git fetch --update-head-ok 10:15:16.425853 git.c:344 trace: built-in: git fetch --update-head-ok 10:15:16.426444 run-command.c:646 trace: run_command: unset GIT_DIR GIT_PREFIX; ssh git@gitlab.alibaba-inc.com 'git-upload-pack ' '' agit/galileo.git'' '' 10:15:16.883780 run-command.c:646 trace: run_command: git rev-list --objects --stdin --not --all --quiet 10:15:16.886473 run-command.c:646 trace: run_command: git rev-list --objects --stdin --not --all --quiet 10:15:16.888001 git.c:344 trace: built-in: git rev-list --objects --stdin --not --all --quiet 10:15:16.926434 run-command.c:1569 run_processes_parallel: preparing to run up to 1 tasks 10:15:16.926536 run-command.c:1601 run_processes_parallel: done 10:15:16.926622 run-command.c:646 trace: run_command: git gc --auto 10:15:16.928214 git.c:344 trace: built-in: git gc --auto 10:15:16.929016 run-command.c:646 trace: run_command: git merge FETCH_HEAD 10:15:16.930404 git.c:344 trace: built-in: git merge FETCH_HEAD $ GIT_TRACE=1 git st 10:18:16.275652 git.c:576 trace: exec : git-st 10:18:16.275723 run-command.c:646 trace: run_command: git-st 10:18:16.275835 git.c:274 trace: alias expansion: st => status 10:18:16.275870 git.c:576 trace: exec : git-status 10:18:16.275876 run-command.c:646 trace: run_command: git-status 10:18:16.277339 git.c:344 trace: built-in: git status On branch master Your branch is up to date with 'origin/master' . nothing to commit, working tree clean
GIT_DIR GIT_CURL_VERBOSE GIT_TRACE_PACKET GIT_TERMINAL_PROMPT GIT_AUTHOR_DATE GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_COMMITTER_DATE GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL
