HG

    Path to the 'hg' executable, automatically passed when running

    hooks, extensions or external tools. If unset or empty, this is

    the hg executable's name if it's frozen, or an executable named

    'hg' (with %PATHEXT% [defaulting to COM/EXE/BAT/CMD] extensions on

    Windows) is searched.

HGEDITOR

    This is the name of the editor to run when committing. See EDITOR.

    (deprecated, see :hg:`help config.ui.editor`)

HGENCODING

    This overrides the default locale setting detected by Mercurial.

    This setting is used to convert data including usernames,

    changeset descriptions, tag names, and branches. This setting can

    be overridden with the --encoding command-line option.

HGENCODINGMODE

    This sets Mercurial's behavior for handling unknown characters

    while transcoding user input. The default is "strict", which

    causes Mercurial to abort if it can't map a character. Other

    settings include "replace", which replaces unknown characters, and

    "ignore", which drops them. This setting can be overridden with

    the --encodingmode command-line option.

HGENCODINGAMBIGUOUS

    This sets Mercurial's behavior for handling characters with

    "ambiguous" widths like accented Latin characters with East Asian

    fonts. By default, Mercurial assumes ambiguous characters are

    narrow, set this variable to "wide" if such characters cause

    formatting problems.

HGMERGE

    An executable to use for resolving merge conflicts. The program

    will be executed with three arguments: local file, remote file,

    ancestor file.

    (deprecated, see :hg:`help config.ui.merge`)

HGRCPATH

    A list of files or directories to search for configuration

    files. Item separator is ":" on Unix, ";" on Windows. If HGRCPATH

    is not set, platform default search path is used. If empty, only

    the .hg/hgrc from the current repository is read.

    For each element in HGRCPATH:

    - if it's a directory, all files ending with .rc are added

    - otherwise, the file itself will be added

HGPLAIN

    When set, this disables any configuration settings that might

    change Mercurial's default output. This includes encoding,

    defaults, verbose mode, debug mode, quiet mode, tracebacks, and

    localization. This can be useful when scripting against Mercurial

    in the face of existing user configuration.

    In addition to the features disabled by ``HGPLAIN=``, the following

    values can be specified to adjust behavior:

    ``+strictflags``

        Restrict parsing of command line flags.

    Equivalent options set via command line flags or environment

    variables are not overridden.

    See :hg:`help scripting` for details.

HGPLAINEXCEPT

    This is a comma-separated list of features to preserve when

    HGPLAIN is enabled. Currently the following values are supported:

    ``alias``

        Don't remove aliases.

    ``color``

        Don't disable colored output.

    ``i18n``

        Preserve internationalization.

    ``revsetalias``

        Don't remove revset aliases.

    ``templatealias``

        Don't remove template aliases.

    ``progress``

        Don't hide progress output.

    Setting HGPLAINEXCEPT to anything (even an empty string) will

    enable plain mode.

HGUSER

    This is the string used as the author of a commit. If not set,

    available values will be considered in this order:

    - HGUSER (deprecated)

    - configuration files from the HGRCPATH

    - EMAIL

    - interactive prompt

    - LOGNAME (with ``@hostname`` appended)

    (deprecated, see :hg:`help config.ui.username`)

EMAIL

    May be used as the author of a commit; see HGUSER.

LOGNAME

    May be used as the author of a commit; see HGUSER.

VISUAL

    This is the name of the editor to use when committing. See EDITOR.

EDITOR

    Sometimes Mercurial needs to open a text file in an editor for a

    user to modify, for example when writing commit messages. The

    editor it uses is determined by looking at the environment

    variables HGEDITOR, VISUAL and EDITOR, in that order. The first

    non-empty one is chosen. If all of them are empty, the editor

    defaults to 'vi'.

PYTHONPATH

    This is used by Python to find imported modules and may need to be

    set appropriately if this Mercurial is not installed system-wide.