$ cat >> $HGRCPATH <<EOF

  > [extensions]

  > convert=

  > [convert]

  > hg.saverev=False

  > EOF

  $ hg help convert

  hg convert [OPTION]... SOURCE [DEST [REVMAP]]

  convert a foreign SCM repository to a Mercurial one.

      Accepted source formats [identifiers]:

      - Mercurial [hg]

      - CVS [cvs]

      - Darcs [darcs]

      - git [git]

      - Subversion [svn]

      - Monotone [mtn]

      - GNU Arch [gnuarch]

      - Bazaar [bzr]

      - Perforce [p4]

      Accepted destination formats [identifiers]:

      - Mercurial [hg]

      - Subversion [svn] (history on branches is not preserved)

      If no revision is given, all revisions will be converted. Otherwise,

      convert will only import up to the named revision (given in a format

      understood by the source).

      If no destination directory name is specified, it defaults to the basename

      of the source with "-hg" appended. If the destination repository doesn't

      exist, it will be created.

      By default, all sources except Mercurial will use --branchsort. Mercurial

      uses --sourcesort to preserve original revision numbers order. Sort modes

      have the following effects:

      --branchsort  convert from parent to child revision when possible, which

                    means branches are usually converted one after the other.

                    It generates more compact repositories.

      --datesort    sort revisions by date. Converted repositories have good-

                    looking changelogs but are often an order of magnitude

                    larger than the same ones generated by --branchsort.

      --sourcesort  try to preserve source revisions order, only supported by

                    Mercurial sources.

      --closesort   try to move closed revisions as close as possible to parent

                    branches, only supported by Mercurial sources.

      If "REVMAP" isn't given, it will be put in a default location

      ("<dest>/.hg/shamap" by default). The "REVMAP" is a simple text file that

      maps each source commit ID to the destination ID for that revision, like

      so:

        <source ID> <destination ID>

      If the file doesn't exist, it's automatically created. It's updated on

      each commit copied, so 'hg convert' can be interrupted and can be run

      repeatedly to copy new commits.

      The authormap is a simple text file that maps each source commit author to

      a destination commit author. It is handy for source SCMs that use unix

      logins to identify authors (e.g.: CVS). One line per author mapping and

      the line format is:

        source author = destination author

      Empty lines and lines starting with a "#" are ignored.

      The filemap is a file that allows filtering and remapping of files and

      directories. Each line can contain one of the following directives:

        include path/to/file-or-dir

        exclude path/to/file-or-dir

        rename path/to/source path/to/destination

      Comment lines start with "#". A specified path matches if it equals the

      full relative name of a file or one of its parent directories. The

      "include" or "exclude" directive with the longest matching path applies,

      so line order does not matter.

      The "include" directive causes a file, or all files under a directory, to

      be included in the destination repository. The default if there are no

      "include" statements is to include everything. If there are any "include"

      statements, nothing else is included. The "exclude" directive causes files

      or directories to be omitted. The "rename" directive renames a file or

      directory if it is converted. To rename from a subdirectory into the root

      of the repository, use "." as the path to rename to.

      "--full" will make sure the converted changesets contain exactly the right

      files with the right content. It will make a full conversion of all files,

      not just the ones that have changed. Files that already are correct will

      not be changed. This can be used to apply filemap changes when converting

      incrementally. This is currently only supported for Mercurial and

      Subversion.

      The splicemap is a file that allows insertion of synthetic history,

      letting you specify the parents of a revision. This is useful if you want

      to e.g. give a Subversion merge two parents, or graft two disconnected

      series of history together. Each entry contains a key, followed by a

      space, followed by one or two comma-separated values:

        key parent1, parent2

      The key is the revision ID in the source revision control system whose

      parents should be modified (same format as a key in .hg/shamap). The

      values are the revision IDs (in either the source or destination revision

      control system) that should be used as the new parents for that node. For

      example, if you have merged "release-1.0" into "trunk", then you should

      specify the revision on "trunk" as the first parent and the one on the

      "release-1.0" branch as the second.

      The branchmap is a file that allows you to rename a branch when it is

      being brought in from whatever external repository. When used in

      conjunction with a splicemap, it allows for a powerful combination to help

      fix even the most badly mismanaged repositories and turn them into nicely

      structured Mercurial repositories. The branchmap contains lines of the

      form:

        original_branch_name new_branch_name

      where "original_branch_name" is the name of the branch in the source

      repository, and "new_branch_name" is the name of the branch is the

      destination repository. No whitespace is allowed in the new branch name.

      This can be used to (for instance) move code in one repository from

      "default" to a named branch.

      Mercurial Source

      ################

      The Mercurial source recognizes the following configuration options, which

      you can set on the command line with "--config":

      convert.hg.ignoreerrors

                    ignore integrity errors when reading. Use it to fix

                    Mercurial repositories with missing revlogs, by converting

                    from and to Mercurial. Default is False.

      convert.hg.saverev

                    store original revision ID in changeset (forces target IDs

                    to change). It takes a boolean argument and defaults to

                    False.

      convert.hg.startrev

                    specify the initial Mercurial revision. The default is 0.

      convert.hg.revs

                    revset specifying the source revisions to convert.

      CVS Source

      ##########

      CVS source will use a sandbox (i.e. a checked-out copy) from CVS to

      indicate the starting point of what will be converted. Direct access to

      the repository files is not needed, unless of course the repository is

      ":local:". The conversion uses the top level directory in the sandbox to

      find the CVS repository, and then uses CVS rlog commands to find files to

      convert. This means that unless a filemap is given, all files under the

      starting directory will be converted, and that any directory

      reorganization in the CVS sandbox is ignored.

      The following options can be used with "--config":

      convert.cvsps.cache

                    Set to False to disable remote log caching, for testing and

                    debugging purposes. Default is True.

      convert.cvsps.fuzz

                    Specify the maximum time (in seconds) that is allowed

                    between commits with identical user and log message in a

                    single changeset. When very large files were checked in as

                    part of a changeset then the default may not be long enough.

                    The default is 60.

      convert.cvsps.logencoding

                    Specify encoding name to be used for transcoding CVS log

                    messages. Multiple encoding names can be specified as a list

                    (see 'hg help config.Syntax'), but only the first acceptable

                    encoding in the list is used per CVS log entries. This

                    transcoding is executed before cvslog hook below.

      convert.cvsps.mergeto

                    Specify a regular expression to which commit log messages

                    are matched. If a match occurs, then the conversion process

                    will insert a dummy revision merging the branch on which

                    this log message occurs to the branch indicated in the

                    regex. Default is "{{mergetobranch ([-\w]+)}}"

      convert.cvsps.mergefrom

                    Specify a regular expression to which commit log messages

                    are matched. If a match occurs, then the conversion process

                    will add the most recent revision on the branch indicated in

                    the regex as the second parent of the changeset. Default is

                    "{{mergefrombranch ([-\w]+)}}"

      convert.localtimezone

                    use local time (as determined by the TZ environment

                    variable) for changeset date/times. The default is False

                    (use UTC).

      hooks.cvslog  Specify a Python function to be called at the end of

                    gathering the CVS log. The function is passed a list with

                    the log entries, and can modify the entries in-place, or add

                    or delete them.

      hooks.cvschangesets

                    Specify a Python function to be called after the changesets

                    are calculated from the CVS log. The function is passed a

                    list with the changeset entries, and can modify the

                    changesets in-place, or add or delete them.

      An additional "debugcvsps" Mercurial command allows the builtin changeset

      merging code to be run without doing a conversion. Its parameters and

      output are similar to that of cvsps 2.1. Please see the command help for

      more details.

      Subversion Source

      #################

      Subversion source detects classical trunk/branches/tags layouts. By

      default, the supplied "svn://repo/path/" source URL is converted as a

      single branch. If "svn://repo/path/trunk" exists it replaces the default

      branch. If "svn://repo/path/branches" exists, its subdirectories are

      listed as possible branches. If "svn://repo/path/tags" exists, it is

      looked for tags referencing converted branches. Default "trunk",

      "branches" and "tags" values can be overridden with following options. Set

      them to paths relative to the source URL, or leave them blank to disable

      auto detection.

      The following options can be set with "--config":

      convert.svn.branches

                    specify the directory containing branches. The default is

                    "branches".

      convert.svn.tags

                    specify the directory containing tags. The default is

                    "tags".

      convert.svn.trunk

                    specify the name of the trunk branch. The default is

                    "trunk".

      convert.localtimezone

                    use local time (as determined by the TZ environment

                    variable) for changeset date/times. The default is False

                    (use UTC).

      Source history can be retrieved starting at a specific revision, instead

      of being integrally converted. Only single branch conversions are

      supported.

      convert.svn.startrev

                    specify start Subversion revision number. The default is 0.

      Git Source

      ##########

      The Git importer converts commits from all reachable branches (refs in

      refs/heads) and remotes (refs in refs/remotes) to Mercurial. Branches are

      converted to bookmarks with the same name, with the leading 'refs/heads'

      stripped. Git submodules are converted to Git subrepos in Mercurial.

      The following options can be set with "--config":

      convert.git.similarity

                    specify how similar files modified in a commit must be to be

                    imported as renames or copies, as a percentage between "0"

                    (disabled) and "100" (files must be identical). For example,

                    "90" means that a delete/add pair will be imported as a

                    rename if more than 90% of the file hasn't changed. The

                    default is "50".

      convert.git.findcopiesharder

                    while detecting copies, look at all files in the working

                    copy instead of just changed ones. This is very expensive

                    for large projects, and is only effective when

                    "convert.git.similarity" is greater than 0. The default is

                    False.

      convert.git.renamelimit

                    perform rename and copy detection up to this many changed

                    files in a commit. Increasing this will make rename and copy

                    detection more accurate but will significantly slow down

                    computation on large projects. The option is only relevant

                    if "convert.git.similarity" is greater than 0. The default

                    is "400".

      convert.git.committeractions

                    list of actions to take when processing author and committer

                    values.

          Git commits have separate author (who wrote the commit) and committer

          (who applied the commit) fields. Not all destinations support separate

          author and committer fields (including Mercurial). This config option

          controls what to do with these author and committer fields during

          conversion.

          A value of "messagedifferent" will append a "committer: ..." line to

          the commit message if the Git committer is different from the author.

          The prefix of that line can be specified using the syntax

          "messagedifferent=<prefix>". e.g. "messagedifferent=git-committer:".

          When a prefix is specified, a space will always be inserted between

          the prefix and the value.

          "messagealways" behaves like "messagedifferent" except it will always

          result in a "committer: ..." line being appended to the commit

          message. This value is mutually exclusive with "messagedifferent".

          "dropcommitter" will remove references to the committer. Only

          references to the author will remain. Actions that add references to

          the committer will have no effect when this is set.

          "replaceauthor" will replace the value of the author field with the

          committer. Other actions that add references to the committer will

          still take effect when this is set.

          The default is "messagedifferent".

      convert.git.extrakeys

                    list of extra keys from commit metadata to copy to the

                    destination. Some Git repositories store extra metadata in

                    commits. By default, this non-default metadata will be lost

                    during conversion. Setting this config option can retain

                    that metadata. Some built-in keys such as "parent" and

                    "branch" are not allowed to be copied.

      convert.git.remoteprefix

                    remote refs are converted as bookmarks with

                    "convert.git.remoteprefix" as a prefix followed by a /. The

                    default is 'remote'.

      convert.git.saverev

                    whether to store the original Git commit ID in the metadata

                    of the destination commit. The default is True.

      convert.git.skipsubmodules

                    does not convert root level .gitmodules files or files with

                    160000 mode indicating a submodule. Default is False.

      Perforce Source

      ###############

      The Perforce (P4) importer can be given a p4 depot path or a client

      specification as source. It will convert all files in the source to a flat

      Mercurial repository, ignoring labels, branches and integrations. Note

      that when a depot path is given you then usually should specify a target

      directory, because otherwise the target may be named "...-hg".

      The following options can be set with "--config":

      convert.p4.encoding

                    specify the encoding to use when decoding standard output of

                    the Perforce command line tool. The default is default

                    system encoding.

      convert.p4.startrev

                    specify initial Perforce revision (a Perforce changelist

                    number).

      Mercurial Destination

      #####################

      The Mercurial destination will recognize Mercurial subrepositories in the

      destination directory, and update the .hgsubstate file automatically if

      the destination subrepositories contain the <dest>/<sub>/.hg/shamap file.

      Converting a repository with subrepositories requires converting a single

      repository at a time, from the bottom up.

      The following options are supported:

      convert.hg.clonebranches

                    dispatch source branches in separate clones. The default is

                    False.

      convert.hg.tagsbranch

                    branch name for tag revisions, defaults to "default".

      convert.hg.usebranchnames

                    preserve branch names. The default is True.

      convert.hg.sourcename

                    records the given string as a 'convert_source' extra value

                    on each commit made in the target repository. The default is

                    None.

      All Destinations

      ################

      All destination types accept the following options:

      convert.skiptags

                    does not convert tags from the source repo to the target

                    repo. The default is False.

  options ([+] can be repeated):

   -s --source-type TYPE source repository type

   -d --dest-type TYPE   destination repository type

   -r --rev REV [+]      import up to source revision REV

   -A --authormap FILE   remap usernames using this file

      --filemap FILE     remap file names using contents of file

      --full             apply filemap changes by converting all files again

      --splicemap FILE   splice synthesized history into place

      --branchmap FILE   change branch names while converting

      --branchsort       try to sort changesets by branches

      --datesort         try to sort changesets by date

      --sourcesort       preserve source changesets order

      --closesort        try to reorder closed revisions

  (some details hidden, use --verbose to show complete help)

  $ hg init a

  $ cd a

  $ echo a > a

  $ hg ci -d'0 0' -Ama

  adding a

  $ hg cp a b

  $ hg ci -d'1 0' -mb