Git rebase error

I managed to create a little mess in my local git repository. I was trying to fix a broken commit by using the following instructions. Before running the «git commit —amend» (and after the git rebase —interactive) I decided that my changes were incorrect and so I executed «git reset HEAD —hard». Not a good idea, I tell you.

Now the interactive rebase seems to be «stuck». Git shows the current branch as (|REBASE-m). Every command (cd .., ls, git rebase…) inside my repository gives the following error:

cat: .git/rebase-merge/head-name: No such file or directory

Here’s how git rebase —abort looks like:

$ git rebase --abort
cat: c:/_work/project/src/git/.git/rebase-merge/quiet: No such file or directory
cat: c:/_work/project/src/git/.git/rebase-merge/head-name: No such file or directory
cat: c:/_work/project/src/git/.git/rebase-merge/orig-head: No such file or directory
HEAD is now at 4c737fb Revert "Modified file names"
rm: cannot remove `c:/_work/project/src/git/.git/rebase-merge/done': Permission denied
rm: cannot remove directory `c:/_work/project/src/git/.git/rebase-merge': Directory
not empty
cat: .git/rebase-merge/head-name: No such file or directory

Here’s the result of git rebase —continue:

$ git rebase --continue
cat: c:/_work/project/src/git/.git/rebase-merge/prev_head: No such file or directory
cat: c:/_work/project/src/git/.git/rebase-merge/end: No such file or directory
cat: c:/_work/project/src/git/.git/rebase-merge/msgnum: No such file or directory
cat: c:/_work/project/src/git/.git/rebase-merge/onto: No such file or directory
cat: c:/_work/project/src/git/.git/rebase-merge/quiet: No such file or directory
prev_head must be defined
cat: .git/rebase-merge/head-name: No such file or directory

Any ideas? I would like to reset the situation back to the state it was before I started my well-thought rebase operation.

Here’s how git log —oneline shows the situation:

4c737fb Revert "Modified file names"
247ac02 Modified file names
33141e6 Message modifications
10a4a04 Modified db script

And this is fine.

I’m using msysgit v1.7.0.2.

Источник

—onto <newbase>

Starting point at which to create the new commits. If the
--onto option is not specified, the starting point is
<upstream>. May be any valid commit, and not just an
existing branch name.

As a special case, you may use «A…B» as a shortcut for the
merge base of A and B if there is exactly one merge base. You can
leave out at most one of A and B, in which case it defaults to HEAD.

—keep-base

Set the starting point at which to create the new commits to the
merge base of <upstream> and <branch>. Running
git rebase --keep-base <upstream> <branch> is equivalent to
running
git rebase --reapply-cherry-picks --no-fork-point --onto <upstream>...<branch> <upstream> <branch>.

This option is useful in the case where one is developing a feature on
top of an upstream branch. While the feature is being worked on, the
upstream branch may advance and it may not be the best idea to keep
rebasing on top of the upstream but to keep the base commit as-is. As
the base commit is unchanged this option implies --reapply-cherry-picks
to avoid losing commits.

Although both this option and --fork-point find the merge base between
<upstream> and <branch>, this option uses the merge base as the starting
point on which new commits will be created, whereas --fork-point uses
the merge base to determine the set of commits which will be rebased.

See also INCOMPATIBLE OPTIONS below.

<upstream>

Upstream branch to compare against. May be any valid commit,
not just an existing branch name. Defaults to the configured
upstream for the current branch.

<branch>

Working branch; defaults to HEAD.

—continue

Restart the rebasing process after having resolved a merge conflict.

—abort

Abort the rebase operation and reset HEAD to the original
branch. If <branch> was provided when the rebase operation was
started, then HEAD will be reset to <branch>. Otherwise HEAD
will be reset to where it was when the rebase operation was
started.

—quit

Abort the rebase operation but HEAD is not reset back to the
original branch. The index and working tree are also left
unchanged as a result. If a temporary stash entry was created
using --autostash, it will be saved to the stash list.

—apply

Use applying strategies to rebase (calling git-am
internally). This option may become a no-op in the future
once the merge backend handles everything the apply one does.

See also INCOMPATIBLE OPTIONS below.

—empty={drop,keep,ask}

How to handle commits that are not empty to start and are not
clean cherry-picks of any upstream commit, but which become
empty after rebasing (because they contain a subset of already
upstream changes). With drop (the default), commits that
become empty are dropped. With keep, such commits are kept.
With ask (implied by --interactive), the rebase will halt when
an empty commit is applied allowing you to choose whether to
drop it, edit files more, or just commit the empty changes.
Other options, like --exec, will use the default of drop unless
-i/--interactive is explicitly specified.

Note that commits which start empty are kept (unless --no-keep-empty
is specified), and commits which are clean cherry-picks (as determined
by git log --cherry-mark ...) are detected and dropped as a
preliminary step (unless --reapply-cherry-picks or --keep-base is
passed).

See also INCOMPATIBLE OPTIONS below.

—no-keep-empty

—keep-empty

Do not keep commits that start empty before the rebase
(i.e. that do not change anything from its parent) in the
result. The default is to keep commits which start empty,
since creating such commits requires passing the --allow-empty
override flag to git commit, signifying that a user is very
intentionally creating such a commit and thus wants to keep
it.

Usage of this flag will probably be rare, since you can get rid of
commits that start empty by just firing up an interactive rebase and
removing the lines corresponding to the commits you don’t want. This
flag exists as a convenient shortcut, such as for cases where external
tools generate many empty commits and you want them all removed.

For commits which do not start empty but become empty after rebasing,
see the --empty flag.

See also INCOMPATIBLE OPTIONS below.

—reapply-cherry-picks

—no-reapply-cherry-picks

Reapply all clean cherry-picks of any upstream commit instead
of preemptively dropping them. (If these commits then become
empty after rebasing, because they contain a subset of already
upstream changes, the behavior towards them is controlled by
the --empty flag.)

In the absence of --keep-base (or if --no-reapply-cherry-picks is
given), these commits will be automatically dropped. Because this
necessitates reading all upstream commits, this can be expensive in
repositories with a large number of upstream commits that need to be
read. When using the merge backend, warnings will be issued for each
dropped commit (unless --quiet is given). Advice will also be issued
unless advice.skippedCherryPicks is set to false (see
git-config[1]).

--reapply-cherry-picks allows rebase to forgo reading all upstream
commits, potentially improving performance.

See also INCOMPATIBLE OPTIONS below.

—allow-empty-message

No-op. Rebasing commits with an empty message used to fail
and this option would override that behavior, allowing commits
with empty messages to be rebased. Now commits with an empty
message do not cause rebasing to halt.

See also INCOMPATIBLE OPTIONS below.

—skip

Restart the rebasing process by skipping the current patch.

—edit-todo

Edit the todo list during an interactive rebase.

—show-current-patch

Show the current patch in an interactive rebase or when rebase
is stopped because of conflicts. This is the equivalent of
git show REBASE_HEAD.

-m

—merge

Using merging strategies to rebase (default).

Note that a rebase merge works by replaying each commit from the working
branch on top of the <upstream> branch. Because of this, when a merge
conflict happens, the side reported as ours is the so-far rebased
series, starting with <upstream>, and theirs is the working branch.
In other words, the sides are swapped.

See also INCOMPATIBLE OPTIONS below.

-s <strategy>

—strategy=<strategy>

Use the given merge strategy, instead of the default ort.
This implies --merge.

Because git rebase replays each commit from the working branch
on top of the <upstream> branch using the given strategy, using
the ours strategy simply empties all patches from the <branch>,
which makes little sense.

See also INCOMPATIBLE OPTIONS below.

-X <strategy-option>

—strategy-option=<strategy-option>

Pass the <strategy-option> through to the merge strategy.
This implies --merge and, if no strategy has been
specified, -s ort. Note the reversal of ours and
theirs as noted above for the -m option.

See also INCOMPATIBLE OPTIONS below.

—rerere-autoupdate

—no-rerere-autoupdate

After the rerere mechanism reuses a recorded resolution on
the current conflict to update the files in the working
tree, allow it to also update the index with the result of
resolution. --no-rerere-autoupdate is a good way to
double-check what rerere did and catch potential
mismerges, before committing the result to the index with a
separate git add.

-S[<keyid>]

—gpg-sign[=<keyid>]

—no-gpg-sign

GPG-sign commits. The keyid argument is optional and
defaults to the committer identity; if specified, it must be
stuck to the option without a space. --no-gpg-sign is useful to
countermand both commit.gpgSign configuration variable, and
earlier --gpg-sign.

-q

—quiet

Be quiet. Implies --no-stat.

-v

—verbose

Be verbose. Implies --stat.

—stat

Show a diffstat of what changed upstream since the last rebase. The
diffstat is also controlled by the configuration option rebase.stat.

-n

—no-stat

Do not show a diffstat as part of the rebase process.

—no-verify

This option bypasses the pre-rebase hook. See also githooks[5].

—verify

Allows the pre-rebase hook to run, which is the default. This option can
be used to override --no-verify. See also githooks[5].

-C<n>

Ensure at least <n> lines of surrounding context match before
and after each change. When fewer lines of surrounding
context exist they all must match. By default no context is
ever ignored. Implies --apply.

See also INCOMPATIBLE OPTIONS below.

—no-ff

—force-rebase

-f

Individually replay all rebased commits instead of fast-forwarding
over the unchanged ones. This ensures that the entire history of
the rebased branch is composed of new commits.

You may find this helpful after reverting a topic branch merge, as this option
recreates the topic branch with fresh commits so it can be remerged
successfully without needing to «revert the reversion» (see the
revert-a-faulty-merge How-To for
details).

—fork-point

—no-fork-point

Use reflog to find a better common ancestor between <upstream>
and <branch> when calculating which commits have been
introduced by <branch>.

When --fork-point is active, fork_point will be used instead of
<upstream> to calculate the set of commits to rebase, where
fork_point is the result of git merge-base --fork-point <upstream> <branch> command (see git-merge-base[1]). If fork_point
ends up being empty, the <upstream> will be used as a fallback.

If <upstream> or --keep-base is given on the command line, then
the default is --no-fork-point, otherwise the default is
--fork-point. See also rebase.forkpoint in git-config[1].

If your branch was based on <upstream> but <upstream> was rewound and
your branch contains commits which were dropped, this option can be used
with --keep-base in order to drop those commits from your branch.

See also INCOMPATIBLE OPTIONS below.

—ignore-whitespace

Ignore whitespace differences when trying to reconcile
differences. Currently, each backend implements an approximation of
this behavior:

apply backend: When applying a patch, ignore changes in whitespace in context
lines. Unfortunately, this means that if the «old» lines being
replaced by the patch differ only in whitespace from the existing
file, you will get a merge conflict instead of a successful patch
application.
merge backend: Treat lines with only whitespace changes as unchanged when merging.
Unfortunately, this means that any patch hunks that were intended
to modify whitespace and nothing else will be dropped, even if the
other side had no changes that conflicted.

—whitespace=<option>

This flag is passed to the git apply program
(see git-apply[1]) that applies the patch.
Implies --apply.

See also INCOMPATIBLE OPTIONS below.

Instead of using the current time as the committer date, use
the author date of the commit being rebased as the committer
date. This option implies --force-rebase.

—ignore-date

—reset-author-date

Instead of using the author date of the original commit, use
the current time as the author date of the rebased commit. This
option implies --force-rebase.

See also INCOMPATIBLE OPTIONS below.

—signoff

Add a Signed-off-by trailer to all the rebased commits. Note
that if --interactive is given then only commits marked to be
picked, edited or reworded will have the trailer added.

See also INCOMPATIBLE OPTIONS below.

-i

—interactive

Make a list of the commits which are about to be rebased. Let the
user edit that list before rebasing. This mode can also be used to
split commits (see SPLITTING COMMITS below).

The commit list format can be changed by setting the configuration option
rebase.instructionFormat. A customized instruction format will automatically
have the long commit hash prepended to the format.

See also INCOMPATIBLE OPTIONS below.

-r

—rebase-merges[=(rebase-cousins|no-rebase-cousins)]

By default, a rebase will simply drop merge commits from the todo
list, and put the rebased commits into a single, linear branch.
With --rebase-merges, the rebase will instead try to preserve
the branching structure within the commits that are to be rebased,
by recreating the merge commits. Any resolved merge conflicts or
manual amendments in these merge commits will have to be
resolved/re-applied manually.

By default, or when no-rebase-cousins was specified, commits which do not
have <upstream> as direct ancestor will keep their original branch point,
i.e. commits that would be excluded by git-log[1]’s
--ancestry-path option will keep their original ancestry by default. If
the rebase-cousins mode is turned on, such commits are instead rebased
onto <upstream> (or <onto>, if specified).

It is currently only possible to recreate the merge commits using the
ort merge strategy; different merge strategies can be used only via
explicit exec git merge -s <strategy> [...] commands.

See also REBASING MERGES and INCOMPATIBLE OPTIONS below.

-x <cmd>

—exec <cmd>

Append «exec <cmd>» after each line creating a commit in the
final history. <cmd> will be interpreted as one or more shell
commands. Any command that fails will interrupt the rebase,
with exit code 1.

You may execute several commands by either using one instance of --exec
with several commands:

git rebase -i --exec "cmd1 && cmd2 && ..."

or by giving more than one --exec:

git rebase -i --exec "cmd1" --exec "cmd2" --exec ...

If --autosquash is used, exec lines will not be appended for
the intermediate commits, and will only appear at the end of each
squash/fixup series.

This uses the --interactive machinery internally, but it can be run
without an explicit --interactive.

See also INCOMPATIBLE OPTIONS below.

—root

Rebase all commits reachable from <branch>, instead of
limiting them with an <upstream>. This allows you to rebase
the root commit(s) on a branch. When used with --onto, it
will skip changes already contained in <newbase> (instead of
<upstream>) whereas without --onto it will operate on every
change.

See also INCOMPATIBLE OPTIONS below.

—autosquash

—no-autosquash

When the commit log message begins with «squash! …» or «fixup! …»
or «amend! …», and there is already a commit in the todo list that
matches the same ..., automatically modify the todo list of
rebase -i, so that the commit marked for squashing comes right after
the commit to be modified, and change the action of the moved commit
from pick to squash or fixup or fixup -C respectively. A commit
matches the ... if the commit subject matches, or if the ... refers
to the commit’s hash. As a fall-back, partial matches of the commit
subject work, too. The recommended way to create fixup/amend/squash
commits is by using the --fixup, --fixup=amend: or --fixup=reword:
and --squash options respectively of git-commit[1].

If the --autosquash option is enabled by default using the
configuration variable rebase.autoSquash, this option can be
used to override and disable this setting.

See also INCOMPATIBLE OPTIONS below.

—autostash

—no-autostash

Automatically create a temporary stash entry before the operation
begins, and apply it after the operation ends. This means
that you can run rebase on a dirty worktree. However, use
with care: the final stash application after a successful
rebase might result in non-trivial conflicts.

—reschedule-failed-exec

—no-reschedule-failed-exec

Automatically reschedule exec commands that failed. This only makes
sense in interactive mode (or when an --exec option was provided).

Even though this option applies once a rebase is started, it’s set for
the whole rebase at the start based on either the
rebase.rescheduleFailedExec configuration (see git-config[1]
or «CONFIGURATION» below) or whether this option is
provided. Otherwise an explicit --no-reschedule-failed-exec at the
start would be overridden by the presence of
rebase.rescheduleFailedExec=true configuration.

—update-refs

—no-update-refs

Automatically force-update any branches that point to commits that
are being rebased. Any branches that are checked out in a worktree
are not updated in this way.

If the configuration variable rebase.updateRefs is set, then this option
can be used to override and disable this setting.

Источник

Resolving conflicts from a Git rebase can be tricky. But don’t worry – here’s a
comprehensive guide to how to resolve them.

There’s three phases:

Which commit of mine is conflicting?
What changes were made in the target branch that conflict with my commit?
Resolve conflicts safely

These are accurate as of Git v2.23 and are for resolving conflicts using the
command line.

Let’s walk through the process.

A conflict happens

On your working branch, you run:

and are faced with a wall-of-text:

Applying: Improve naming around create-import-process end-point
Recorded resolution for 'src/octoenergy/interfaces/apisite/data_import/views.py'.
Applying: Extract serializer creation into own method
Using index info to reconstruct a base tree...
M src/octoenergy/interfaces/apisite/data_import/views.py
Falling back to patching base and 3-way merge...
Auto-merging src/octoenergy/interfaces/apisite/data_import/views.py
Applying: Group tests into classes for Account data-import serializer
Using index info to reconstruct a base tree...
M src/tests/unit/common/domain/data_import/validation/test_accounts.py
Falling back to patching base and 3-way merge...
Auto-merging src/tests/unit/common/domain/data_import/validation/test_accounts.py
CONFLICT (content): Merge conflict in src/tests/unit/common/domain/data_import/validation/test_accounts.py
Recorded preimage for 'src/tests/unit/common/domain/data_import/validation/test_accounts.py'
error: Failed to merge in the changes.
Patch failed at 0003 Group tests into classes for Account data-import serializer
hint: Use 'git am --show-current-patch' to see the failed patch
Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".

Conflicts? Conflicts!

Often the conflicts are simple and easily resolved by eye-balling the files in
question. If that’s true, good for you: resolve the conflicts using your
favourite editor and move on via:

However, if the conflicts are not trivially resolved, start by asking yourself
this:

Which commit of mine is conflicting?

We can identify the conflicting commit in several ways:

Look for the Patch failed at $NUMBER $SUBJECT line in the rebase output.
This prints the subject of the commit that couldn’t be applied. In the above
example, the offending commit has subject
Group tests into class for Account data-import serializer.
Alternatively, follow the advice in the rebase output and run:
```
git am --show-current-patch
```
which is equivalent to running git show on the conflicting commit.
As of Git v2.17, this option can be used with git rebase too:
```
git rebase --show-current-patch
```
Best of all, there is a REBASE_HEAD pseudo-ref that points to the
conflicting commit, so you can do:

to view the commit, or:
```
git rev-parse REBASE_HEAD
```
to see the commit SHA.

It can be useful to open the Github detail page for the offending commit to
allow a quick glance at the diff in another window. If you use hub (and
Github), this can done with:

hub browse -- commit/$(git rev-parse REBASE_HEAD)

which, if you find it useful, could be alised as:

[alias]
openconflict = "!f() { hub browse -- commit/$(git rev-parse REBASE_HEAD); }; f"

in ~/.gitconfig.

Now for the trickier question.

What changes were made in the target branch that conflict with my commit?

We understand what we were trying to do, but we need to understand what
changes were made in the target branch that conflict. Two tips:

Use the `diff3` format to see common ancestor code in conflict blocks

Globally enable this with:

git config --global merge.conflictstyle diff3

and then conflict blocks will be formatted like:

<<<<<<<< HEAD:path/to/file
content from target branch
|||||||| merged common ancestors:path/to/file
common ancestor content
========
content from your working branch
>>>>>>> Commit message:path/to/file

where the default conflict block has been extended with a new section, delimited
by |||||||| and ========, which reveals the common ancestor code.

Comparing the HEAD block to the common ancestor block will often reveal the
nature of the target-branch changes, allowing a straight-forward resolution.

For instance, breath easy if the common ancestor block is empty:

<<<<<<<< HEAD:path/to/file
content from target branch
|||||||| merged common ancestors:path/to/file
========
content from your working branch
>>>>>>> Commit message:path/to/file

as this means both branches have added lines; they haven’t tried to update the
same lines. You can simply delete the merge conflict markers to resolve.

If eyeballing the conflicts is not sufficient to safely resolve, we need to dig
deeper.

Examine the target branch changes in detail

Sometimes the conflicted blocks are large and you can’t understand at a glance
what changes have been made in the target branch and why they were made. In this
situation, we may need to examine the individual changes made to each conflicted
$FILEPATH in order to understand how to resolve safely.

We can examine the overall diff:

git diff REBASE_HEAD...origin/master $FILEPATH

or list the commits from the target branch that updated $FILEPATH:

git log REBASE_HEAD..origin/master $FILEPATH

and review how each modified $FILEPATH with:

git show $COMMIT_SHA -- $FILEPATH

Note the git diff command uses three dots while the git log command uses
two.

If there are lots of commits that modified $FILEPATH, it can be helpful to run
git blame and see which commits updated the conflicting block and focus your
attention on those.

This should provide enough information to understand the changes from the target
branch so you can resolve the conflicts.

Resolve conflicts safely

A couple of things:

Apply your changes to the target branch code

When manually editing conflicted files, always resolve conflicts by applying
your changes to the target branch block (labelled HEAD) as you understand your
changes better and are less likely to inadvertently break something.

For example: in the following diff:

<<<<<<<< HEAD
I like apples and pears
|||||||| merged common ancestors
I like apples
========
I love apples
>>>>>>> branch-a

Apply your change (replacing “like” with “love”) to the HEAD block to give:

<<<<<<<< HEAD
I love apples and pears
|||||||| merged common ancestors
I like apples
========
I love apples
>>>>>>> working-branch

then remove the superceded lines and merge conflict markers to give:

Wholesale accept changes

Occassionally, you might know that the changes from one branch should be
accepted. This can be done using git checkout with a merge “strategy-option”.
Beware that, when rebasing, the terminology is counter-intuitive.

To accept the changes from the target branch, use:

git checkout --ours -- $FILEPATH

To accept the changes made on your working branch, use:

git checkout --theirs -- $FILEPATH

As a rebase involves replaying your commits to the tip of the target branch,
each replayed commit is treated as “theirs” (even though you are the author)
while the existing target branch commits are “ours”.

Even more sweepingly, you can auto-resolve conflicts using a specified strategy
when doing the rebase. Eg:

git rebase -Xtheirs origin/master

I’ve never used this much in practice though.

Re-use recorded resolutions (aka `rerere`)

If you set:

git config --global rerere.enabled 1

then Git will record how you resolve conflicts and, if it sees the same conflict
during a future rebase (eg if you --abort then retry), it will automatically
resolve the conflict for you.

You can see evidence of rerere in action in the git rebase output. You’ll
see:

Recorded preimage for '...'

when Git detects a conflicted file, then:

Recorded resolution for '...'

when Git records the resolution (to .git/rr-cache/), and finally:

Resolved '...' using previous resolution.

when Git re-uses the saved resolution.

You should enable this – there’s no downside.

Summary

Hopefully the above is useful.

Resolving rebase conflicts is much easier if commits are “atomic”, with each
change motivated by a single reason (similar to the
Single Responsibility Principle).
For instance, never mix file-system changes (ie moving files around) with core
logic changes. Such commits are likely to attract conflicts and are hard to
resolve.

Don’t worry if the rebase gets away from you; you can always abort with:

if things become too hairy.

A conflict happens

Which commit of mine is conflicting?

What changes were made in the target branch that conflict with my commit?

Use the `diff3` format to see common ancestor code in conflict blocks

Examine the target branch changes in detail

Resolve conflicts safely

Apply your changes to the target branch code

Wholesale accept changes

Re-use recorded resolutions (aka `rerere`)

Summary

Further reading

Читайте также:

A conflict happens

Which commit of mine is conflicting?

What changes were made in the target branch that conflict with my commit?

Use the diff3 format to see common ancestor code in conflict blocks

Examine the target branch changes in detail

Resolve conflicts safely

Apply your changes to the target branch code

Wholesale accept changes

Re-use recorded resolutions (aka rerere)

Summary

Further reading

Читайте также:

Use the `diff3` format to see common ancestor code in conflict blocks

Re-use recorded resolutions (aka `rerere`)