Some Mercurial commands deal with writing patches. On these there is an option "--git".

Excerpt from 'hg help export':

    Use the -g/--git option to generate diffs in the git extended diff
    format. See 'hg help diffs' for more information.

'hg help' topic about diffs

Mercurial has a special help topic about diffs (

> hg help diffs
Diff Formats

    Mercurial's default format for showing changes between two
    versions of a file is compatible with the unified format of GNU
    diff, which can be used by GNU patch and many other standard

    While this standard format is often enough, it does not encode the
    following information:

     - executable status and other permission bits
     - copy or rename information
     - changes in binary files
     - creation or deletion of empty files

    Mercurial also supports the extended diff format from the git VCS
    which addresses these limitations. The git diff format is not
    produced by default because a few widespread tools still do not
    understand this format.

    This means that when generating diffs from a Mercurial repository
    (e.g. with "hg export"), you should be careful about things like
    file copies and renames or other things mentioned above, because
    when applying a standard diff to a different repository, this
    extra information is lost. Mercurial's internal operations (like
    push and pull) are not affected by this, because they use an
    internal binary format for communicating changes.

    To make Mercurial produce the git extended diff format, use the
    --git option available for many commands, or set 'git = True' in
    the [diff] section of your hgrc. You do not need to set this
    option when importing diffs in this format or using them in the mq

Recurring topic on mailing lists

Asking for defining the --git option as a default is a recurring topic on the mailing lists.

Matt Mackall summarized on 2009-08-16 his decisions on the topic as follows (

Here's how this topic goes, every time for the past four years:

Q: Can we make --git the default?
A: No, it's non-standard.
Q: How about just for mq?
A: No.
Q: Can we get a warning or something when a patch is going to lose
A: Sounds great, send a patch.

Support was added in mq for versions 1.4.3 and later. See for more details about configuration.

Relevant issues in bug tracker

See also


GitExtendedDiffFormat (last edited 2019-06-07 09:17:54 by aayjaychan)