Git push to GitHub error solution - Andy's Blog

前言

今天想把自己网站的源代码上传到GitHub仓库里保存，这样之后也可以在多台电脑上操作了。但用Git push到GitHub时出错了，我想应该是之前把这个源代码在不同的电脑上到处拷贝操作上传导致版本信息不一致导致的。所以有了如下操作及解决过程。

过程

Last login: Wed Feb  1 13:57:43 on console
andy@Andy-iMacPro ~ % cd Repo/MyBlog

andy@Andy-iMacPro MyBlog % git add .

andy@Andy-iMacPro MyBlog % git commit -m "jinchuan site source code" 
[main 44b58ad] jinchuan site source code
 3 files changed, 136 insertions(+), 17 deletions(-)
 create mode 100644 source/_posts/RaspberryPi-Fan-Control-Based-on-Temperature.md

andy@Andy-iMacPro MyBlog % git branch -M main

andy@Andy-iMacPro MyBlog % git remote add origin https://github.com/JinchuanL/jinchuan.site.git
error: remote origin already exists.

andy@Andy-iMacPro MyBlog % git push -u origin main
To https://github.com/JinchuanL/jinchuan.site.git
 ! [rejected]        main -> main (non-fast-forward)
error: failed to push some refs to 'https://github.com/JinchuanL/jinchuan.site.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

andy@Andy-iMacPro MyBlog % git pull
There is no tracking information for the current branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>

If you wish to set tracking information for this branch you can do so with:

    git branch --set-upstream-to=origin/<branch> main

andy@Andy-iMacPro MyBlog % git pull https://github.com/JinchuanL/jinchuan.site.git main
From https://github.com/JinchuanL/jinchuan.site
 * branch            main       -> FETCH_HEAD
hint: You have divergent branches and need to specify how to reconcile them.
hint: You can do so by running one of the following commands sometime before
hint: your next pull:
hint: 
hint:   git config pull.rebase false  # merge
hint:   git config pull.rebase true   # rebase
hint:   git config pull.ff only       # fast-forward only
hint: 
hint: You can replace "git config" with "git config --global" to set a default
hint: preference for all repositories. You can also pass --rebase, --no-rebase,
hint: or --ff-only on the command line to override the configured default per
hint: invocation.
fatal: Need to specify how to reconcile divergent branches.

andy@Andy-iMacPro MyBlog % git pull --ff-only https://github.com/JinchuanL/jinchuan.site.git main
From https://github.com/JinchuanL/jinchuan.site
 * branch            main       -> FETCH_HEAD
fatal: Not possible to fast-forward, aborting.

andy@Andy-iMacPro MyBlog % git rebase main 
Current branch main is up to date.

andy@Andy-iMacPro MyBlog % git rebase https://github.com/JinchuanL/jinchuan.site.git main
fatal: invalid upstream 'https://github.com/JinchuanL/jinchuan.site.git'

andy@Andy-iMacPro MyBlog % git rebase https://github.com/JinchuanL/jinchuan.site.git    
fatal: invalid upstream 'https://github.com/JinchuanL/jinchuan.site.git'

andy@Andy-iMacPro MyBlog % git rebase main                                     
Current branch main is up to date.

andy@Andy-iMacPro MyBlog % git pull https://github.com/JinchuanL/jinchuan.site.git main
From https://github.com/JinchuanL/jinchuan.site
 * branch            main       -> FETCH_HEAD
hint: You have divergent branches and need to specify how to reconcile them.
hint: You can do so by running one of the following commands sometime before
hint: your next pull:
hint: 
hint:   git config pull.rebase false  # merge
hint:   git config pull.rebase true   # rebase
hint:   git config pull.ff only       # fast-forward only
hint: 
hint: You can replace "git config" with "git config --global" to set a default
hint: preference for all repositories. You can also pass --rebase, --no-rebase,
hint: or --ff-only on the command line to override the configured default per
hint: invocation.
fatal: Need to specify how to reconcile divergent branches.

andy@Andy-iMacPro MyBlog % git pull.rebase true https://github.com/JinchuanL/jinchuan.site.git main
git: 'pull.rebase' is not a git command. See 'git --help'.

andy@Andy-iMacPro MyBlog % git config pull.rebase true 

andy@Andy-iMacPro MyBlog % git pull https://github.com/JinchuanL/jinchuan.site.git main
From https://github.com/JinchuanL/jinchuan.site
 * branch            main       -> FETCH_HEAD
warning: unable to rmdir 'themes/hexo-theme-cupertino': Directory not empty
Successfully rebased and updated refs/heads/main.

andy@Andy-iMacPro MyBlog % git push -u origin main
Enumerating objects: 68, done.
Counting objects: 100% (68/68), done.
Delta compression using up to 12 threads
Compressing objects: 100% (52/52), done.
Writing objects: 100% (67/67), 1.76 MiB | 892.00 KiB/s, done.
Total 67 (delta 5), reused 0 (delta 0), pack-reused 0
^C

andy@Andy-iMacPro MyBlog % killall ssh-agent; eval `ssh-agent`
No matching processes belonging to you were found
Agent pid 1347

andy@Andy-iMacPro MyBlog % git push -u origin main            
Enumerating objects: 68, done.
Counting objects: 100% (68/68), done.
Delta compression using up to 12 threads
Compressing objects: 100% (52/52), done.
Writing objects: 100% (67/67), 1.76 MiB | 2.76 MiB/s, done.
Total 67 (delta 5), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (5/5), done.
To https://github.com/JinchuanL/jinchuan.site.git
   bd20a3d..5259aad  main -> main
branch 'main' set up to track 'origin/main'.

andy@Andy-iMacPro MyBlog % git config pull.rebase false

andy@Andy-iMacPro MyBlog % git pull https://github.com/JinchuanL/jinchuan.site.git main
From https://github.com/JinchuanL/jinchuan.site
 * branch            main       -> FETCH_HEAD
Already up to date.

andy@Andy-iMacPro MyBlog % git push -u origin main     
branch 'main' set up to track 'origin/main'.
Everything up-to-date

解决思路

• Fatal: Not possible to fast-forward, aborting

  Your branch is no longer directly based off of the branch you’re trying to merge it into - e.g. another commit was added to the destination branch that isn’t in your branch. Thus, you can’t fast-forward into it (because fast-forward requires your branch to completely contain the destination branch).

  You can rebase your branch on top of the destination branch (git rebase <destination branch>) to rework the commits such that they will fast forward into it, or you can do a regular merge.

  Maybe try

  git pull origin <branch> --rebase

  
  

• “You have divergent branches and need to specify how to reconcile them.” #14431

  Working solution:

  @aenzor This is a message that started showing up in Git v2.27 in the command line. You can choose one of the options mentioned in the hints to stop it from occurring. The git config pull.rebase false is the default setting. You can read more about the settings in the official Git docs. GitHub Desktop will respect your choice in the global .gitconfig.

  Possible solution:

  We are looking at a more ideal solution for this through Desktop, but in the mean time. For those unfamiliar with using the Command Line Interface (CLI).

  1. From GitHub Desktop, you can press Ctrl + ` (Also available from the “Repository” main menu as “Open in [Your set terminal]”). This should open up a CLI.

  2. There you can type:
     git config --global pull.ff true (or any of the other options specified in the error hints).

  3. Now when you attempt to pull it will use that configuration and allow you to continue.

  There is the possibility that because you do not use the CLI, you may need to download and install git for this to work.

  Some explanation of choice above if interested:
  I suggested pull.ff true simply because it attempts to fast forward your branch to be up to date with your remote before applying your local commits and if not it will preform a merge from the remote to your local branch. Read docs here. Typically when you pull a branch, add commits, and push. It is in the order assuming your local is up to date with remote. By merging when fast forwarding is not possible, you will see a merge commit informing you of how it was handled. (The other options are to rebase or always merge, many new users find rebase to be less intuitive, but really accomplishes the same thing)

  I added the –global flag so that your choice will apply to all your repos and you won’t see this error message again. Simply omit this if you want a different behavior per repository.

• How can I deal with this Git warning? “Pulling without specifying how to reconcile divergent branches is discouraged”

  In its default mode, git pull is shorthand for git fetch followed by git merge FETCH_HEAD.

  When you do a git pull origin master,
  git pull performs a merge, which often creates a merge commit. Therefore, by default, pulling from the remote is not a harmless operation: it can create a new commit SHA hash value that didn’t exist before. This behavior can confuse a user, because what feels like it should be a harmless download operation actually changes the commit history in unpredictable ways.

  To avoid this, you need

  git pull –ff-only
  (or not? read on to see which one fits your requirements)

  With git pull –ff-only, Git will update your branch only if it can be “fast-forwarded” without creating new commits. If this can’t be done, git pull –ff-only simply aborts with an error message.

  You can configure your Git client to always use –ff-only by default, so you get this behavior even if you forget the command-line flag:

  git config –global pull.ff only
  Note: The –global flag applies the change for all repositories on your machine. If you want this behaviour only for the repository you’re in, omit the flag.

• Terminal stuck when pushing to GitHub?

  # Restart your ssh agent!
  killall ssh-agent; eval `ssh-agent`

总结

换电脑或者版本信息不一致时，建议走如下流程

# main: my branch, replace main or switch to others based your situation
git rebase main 

# Set rebase to true when do a pull request, by default it is false
git config pull.rebase true 

# Try pull request again
# git pull <source> <branch>
git pull https://github.com/JinchuanL/jinchuan.site.git main
$Successfully rebased and updated refs/heads/main. # Looks all good

# Then we can push our local repo to GitHub repo now.
git push -u origin main

# Personally, I like to put things back to it's original place
# So one more step, put pull.rebase back to false so next time when we do a pull request, it won't rebase again
git config pull.rebase false

# Check
git config pull.rebase
$false	# All good, already change back to origin place

# If Terminal stucks when trying to push to GitHub
# Restart your ssh agent!
killall ssh-agent; eval `ssh-agent`
# And try to push again

Reference

• Git push hangs when pushing to Github?
• Reconcile divergent branches #14423
• “You have divergent branches and need to specify how to reconcile them.” #14431
• How can I deal with this Git warning? “Pulling without specifying how to reconcile divergent branches is discouraged”
• Fatal: Not possible to fast-forward, aborting