Documentation/git-cvsserver.txt - git - Git at Google

 git-cvsserver(1)
 ================

 NAME
 ----
 git-cvsserver - A CVS server emulator for Git

 SYNOPSIS
 --------

 SSH:

 [verse]
 export CVS_SERVER="git cvsserver"
 'cvs' -d :ext:user@server/path/repo.git co <HEAD_name>

 pserver (/etc/inetd.conf):

 [verse]
 cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver

 Usage:

 [verse]
 'git-cvsserver' [options] [pserver|server] [<directory> ...]

 OPTIONS
 -------

 All these options obviously only make sense if enforced by the server side.
 They have been implemented to resemble the linkgit:git-daemon[1] options as
 closely as possible.

 --base-path <path>::
 Prepend 'path' to requested CVSROOT

 --strict-paths::
 Don't allow recursing into subdirectories

 --export-all::
 Don't check for `gitcvs.enabled` in config. You also have to specify a list
 of allowed directories (see below) if you want to use this option.

 -V::
 --version::
 Print version information and exit

 -h::
 -H::
 --help::
 Print usage information and exit

 <directory>::
 You can specify a list of allowed directories. If no directories
 are given, all are allowed. This is an additional restriction, gitcvs
 access still needs to be enabled by the `gitcvs.enabled` config option
 unless '--export-all' was given, too.


 DESCRIPTION
 -----------

 This application is a CVS emulation layer for Git.

 It is highly functional. However, not all methods are implemented,
 and for those methods that are implemented,
 not all switches are implemented.

 Testing has been done using both the CLI CVS client, and the Eclipse CVS
 plugin. Most functionality works fine with both of these clients.

 LIMITATIONS
 -----------

 CVS clients cannot tag, branch or perform Git merges.

 'git-cvsserver' maps Git branches to CVS modules. This is very different
 from what most CVS users would expect since in CVS modules usually represent
 one or more directories.

 INSTALLATION
 ------------

 1. If you are going to offer CVS access via pserver, add a line in
    /etc/inetd.conf like
 +
 --
 ------
    cvspserver stream tcp nowait nobody git-cvsserver pserver

 ------
 Note: Some inetd servers let you specify the name of the executable
 independently of the value of argv[0] (i.e. the name the program assumes
 it was executed with). In this case the correct line in /etc/inetd.conf
 looks like

 ------
    cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver

 ------

 Only anonymous access is provided by pserve by default. To commit you
 will have to create pserver accounts, simply add a gitcvs.authdb
 setting in the config file of the repositories you want the cvsserver
 to allow writes to, for example:

 ------

    [gitcvs]
 	authdb = /etc/cvsserver/passwd

 ------
 The format of these files is username followed by the crypted password,
 for example:

 ------
    myuser:$1Oyx5r9mdGZ2
    myuser:$1$BA)@$vbnMJMDym7tA32AamXrm./
 ------
 You can use the 'htpasswd' facility that comes with Apache to make these
 files, but Apache's MD5 crypt method differs from the one used by most C
 library's crypt() function, so don't use the -m option.

 Alternatively you can produce the password with perl's crypt() operator:
 -----
    perl -e 'my ($user, $pass) = @ARGV; printf "%s:%s\n", $user, crypt($user, $pass)' $USER password
 -----

 Then provide your password via the pserver method, for example:
 ------
    cvs -d:pserver:someuser:somepassword <at> server/path/repo.git co <HEAD_name>
 ------
 No special setup is needed for SSH access, other than having Git tools
 in the PATH. If you have clients that do not accept the CVS_SERVER
 environment variable, you can rename 'git-cvsserver' to `cvs`.

 Note: Newer CVS versions (>= 1.12.11) also support specifying
 CVS_SERVER directly in CVSROOT like

 ------
 cvs -d ":ext;CVS_SERVER=git cvsserver:user@server/path/repo.git" co <HEAD_name>
 ------
 This has the advantage that it will be saved in your 'CVS/Root' files and
 you don't need to worry about always setting the correct environment
 variable.  SSH users restricted to 'git-shell' don't need to override the default
 with CVS_SERVER (and shouldn't) as 'git-shell' understands `cvs` to mean
 'git-cvsserver' and pretends that the other end runs the real 'cvs' better.
 --
 2. For each repo that you want accessible from CVS you need to edit config in
    the repo and add the following section.
 +
 --
 ------
    [gitcvs]
         enabled=1
         # optional for debugging
         logfile=/path/to/logfile

 ------
 Note: you need to ensure each user that is going to invoke 'git-cvsserver' has
 write access to the log file and to the database (see
 <<dbbackend,Database Backend>>. If you want to offer write access over
 SSH, the users of course also need write access to the Git repository itself.

 You also need to ensure that each repository is "bare" (without a Git index
 file) for `cvs commit` to work. See linkgit:gitcvs-migration[7].

 [[configaccessmethod]]
 All configuration variables can also be overridden for a specific method of
 access. Valid method names are "ext" (for SSH access) and "pserver". The
 following example configuration would disable pserver access while still
 allowing access over SSH.
 ------
    [gitcvs]
         enabled=0

    [gitcvs "ext"]
         enabled=1
 ------
 --
 3. If you didn't specify the CVSROOT/CVS_SERVER directly in the checkout command,
    automatically saving it in your 'CVS/Root' files, then you need to set them
    explicitly in your environment.  CVSROOT should be set as per normal, but the
    directory should point at the appropriate Git repo.  As above, for SSH clients
    _not_ restricted to 'git-shell', CVS_SERVER should be set to 'git-cvsserver'.
 +
 --
 ------
      export CVSROOT=:ext:user@server:/var/git/project.git
      export CVS_SERVER="git cvsserver"
 ------
 --
 4. For SSH clients that will make commits, make sure their server-side
    .ssh/environment files (or .bashrc, etc., according to their specific shell)
    export appropriate values for GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL,
    GIT_COMMITTER_NAME, and GIT_COMMITTER_EMAIL.  For SSH clients whose login
    shell is bash, .bashrc may be a reasonable alternative.

 5. Clients should now be able to check out the project. Use the CVS 'module'
    name to indicate what Git 'head' you want to check out.  This also sets the
    name of your newly checked-out directory, unless you tell it otherwise with
    `-d <dir_name>`.  For example, this checks out 'master' branch to the
    `project-master` directory:
 +
 ------
      cvs co -d project-master master
 ------

 [[dbbackend]]
 Database Backend
 ----------------

 'git-cvsserver' uses one database per Git head (i.e. CVS module) to
 store information about the repository to maintain consistent
 CVS revision numbers. The database needs to be
 updated (i.e. written to) after every commit.

 If the commit is done directly by using `git` (as opposed to
 using 'git-cvsserver') the update will need to happen on the
 next repository access by 'git-cvsserver', independent of
 access method and requested operation.

 That means that even if you offer only read access (e.g. by using
 the pserver method), 'git-cvsserver' should have write access to
 the database to work reliably (otherwise you need to make sure
 that the database is up-to-date any time 'git-cvsserver' is executed).

 By default it uses SQLite databases in the Git directory, named
 `gitcvs.<module_name>.sqlite`. Note that the SQLite backend creates
 temporary files in the same directory as the database file on
 write so it might not be enough to grant the users using
 'git-cvsserver' write access to the database file without granting
 them write access to the directory, too.

 The database can not be reliably regenerated in a
 consistent form after the branch it is tracking has changed.
 Example: For merged branches, 'git-cvsserver' only tracks
 one branch of development, and after a 'git merge' an
 incrementally updated database may track a different branch
 than a database regenerated from scratch, causing inconsistent
 CVS revision numbers. `git-cvsserver` has no way of knowing which
 branch it would have picked if it had been run incrementally
 pre-merge. So if you have to fully or partially (from old
 backup) regenerate the database, you should be suspicious
 of pre-existing CVS sandboxes.

 You can configure the database backend with the following
 configuration variables:

 Configuring database backend
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 'git-cvsserver' uses the Perl DBI module. Please also read
 its documentation if changing these variables, especially
 about `DBI->connect()`.

 gitcvs.dbname::
 	Database name. The exact meaning depends on the
 	selected database driver, for SQLite this is a filename.
 	Supports variable substitution (see below). May
 	not contain semicolons (`;`).
 	Default: '%Ggitcvs.%m.sqlite'

 gitcvs.dbdriver::
 	Used DBI driver. You can specify any available driver
 	for this here, but it might not work. cvsserver is tested
 	with 'DBD::SQLite', reported to work with
 	'DBD::Pg', and reported *not* to work with 'DBD::mysql'.
 	Please regard this as an experimental feature. May not
 	contain colons (`:`).
 	Default: 'SQLite'

 gitcvs.dbuser::
 	Database user. Only useful if setting `dbdriver`, since
 	SQLite has no concept of database users. Supports variable
 	substitution (see below).

 gitcvs.dbpass::
 	Database password.  Only useful if setting `dbdriver`, since
 	SQLite has no concept of database passwords.

 gitcvs.dbTableNamePrefix::
 	Database table name prefix.  Supports variable substitution
 	(see below).  Any non-alphabetic characters will be replaced
 	with underscores.

 All variables can also be set per access method, see <<configaccessmethod,above>>.

 Variable substitution
 ^^^^^^^^^^^^^^^^^^^^^
 In `dbdriver` and `dbuser` you can use the following variables:

 %G::
 	Git directory name
 %g::
 	Git directory name, where all characters except for
 	alpha-numeric ones, `.`, and `-` are replaced with
 	`_` (this should make it easier to use the directory
 	name in a filename if wanted)
 %m::
 	CVS module/Git head name
 %a::
 	access method (one of "ext" or "pserver")
 %u::
 	Name of the user running 'git-cvsserver'.
 	If no name can be determined, the
 	numeric uid is used.

 ENVIRONMENT
 -----------

 These variables obviate the need for command-line options in some
 circumstances, allowing easier restricted usage through git-shell.

 GIT_CVSSERVER_BASE_PATH takes the place of the argument to --base-path.

 GIT_CVSSERVER_ROOT specifies a single-directory whitelist. The
 repository must still be configured to allow access through
 git-cvsserver, as described above.

 When these environment variables are set, the corresponding
 command-line arguments may not be used.

 Eclipse CVS Client Notes
 ------------------------

 To get a checkout with the Eclipse CVS client:

 1. Select "Create a new project -> From CVS checkout"
 2. Create a new location. See the notes below for details on how to choose the
    right protocol.
 3. Browse the 'modules' available. It will give you a list of the heads in
    the repository. You will not be able to browse the tree from there. Only
    the heads.
 4. Pick 'HEAD' when it asks what branch/tag to check out. Untick the
    "launch commit wizard" to avoid committing the .project file.

 Protocol notes: If you are using anonymous access via pserver, just select that.
 Those using SSH access should choose the 'ext' protocol, and configure 'ext'
 access on the Preferences->Team->CVS->ExtConnection pane. Set CVS_SERVER to
 "`git cvsserver`". Note that password support is not good when using 'ext',
 you will definitely want to have SSH keys setup.

 Alternatively, you can just use the non-standard extssh protocol that Eclipse
 offer. In that case CVS_SERVER is ignored, and you will have to replace
 the cvs utility on the server with 'git-cvsserver' or manipulate your `.bashrc`
 so that calling 'cvs' effectively calls 'git-cvsserver'.

 Clients known to work
 ---------------------

 - CVS 1.12.9 on Debian
 - CVS 1.11.17 on MacOSX (from Fink package)
 - Eclipse 3.0, 3.1.2 on MacOSX (see Eclipse CVS Client Notes)
 - TortoiseCVS

 Operations supported
 --------------------

 All the operations required for normal use are supported, including
 checkout, diff, status, update, log, add, remove, commit.

 Most CVS command arguments that read CVS tags or revision numbers
 (typically -r) work, and also support any git refspec
 (tag, branch, commit ID, etc).
 However, CVS revision numbers for non-default branches are not well
 emulated, and cvs log does not show tags or branches at
 all.  (Non-main-branch CVS revision numbers superficially resemble CVS
 revision numbers, but they actually encode a git commit ID directly,
 rather than represent the number of revisions since the branch point.)

 Note that there are two ways to checkout a particular branch.
 As described elsewhere on this page, the "module" parameter
 of cvs checkout is interpreted as a branch name, and it becomes
 the main branch.  It remains the main branch for a given sandbox
 even if you temporarily make another branch sticky with
 cvs update -r.  Alternatively, the -r argument can indicate
 some other branch to actually checkout, even though the module
 is still the "main" branch.  Tradeoffs (as currently
 implemented): Each new "module" creates a new database on disk with
 a history for the given module, and after the database is created,
 operations against that main branch are fast.  Or alternatively,
 -r doesn't take any extra disk space, but may be significantly slower for
 many operations, like cvs update.

 If you want to refer to a git refspec that has characters that are
 not allowed by CVS, you have two options.  First, it may just work
 to supply the git refspec directly to the appropriate CVS -r argument;
 some CVS clients don't seem to do much sanity checking of the argument.
 Second, if that fails, you can use a special character escape mechanism
 that only uses characters that are valid in CVS tags.  A sequence
 of 4 or 5 characters of the form (underscore (`"_"`), dash (`"-"`),
 one or two characters, and dash (`"-"`)) can encode various characters based
 on the one or two letters: `"s"` for slash (`"/"`), `"p"` for
 period (`"."`), `"u"` for underscore (`"_"`), or two hexadecimal digits
 for any byte value at all (typically an ASCII number, or perhaps a part
 of a UTF-8 encoded character).

 Legacy monitoring operations are not supported (edit, watch and related).
 Exports and tagging (tags and branches) are not supported at this stage.

 CRLF Line Ending Conversions
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 By default the server leaves the '-k' mode blank for all files,
 which causes the CVS client to treat them as a text files, subject
 to end-of-line conversion on some platforms.

 You can make the server use the end-of-line conversion attributes to
 set the '-k' modes for files by setting the `gitcvs.usecrlfattr`
 config variable.  See linkgit:gitattributes[5] for more information
 about end-of-line conversion.

 Alternatively, if `gitcvs.usecrlfattr` config is not enabled
 or the attributes do not allow automatic detection for a filename, then
 the server uses the `gitcvs.allbinary` config for the default setting.
 If `gitcvs.allbinary` is set, then file not otherwise
 specified will default to '-kb' mode. Otherwise the '-k' mode
 is left blank. But if `gitcvs.allbinary` is set to "guess", then
 the correct '-k' mode will be guessed based on the contents of
 the file.

 For best consistency with 'cvs', it is probably best to override the
 defaults by setting `gitcvs.usecrlfattr` to true,
 and `gitcvs.allbinary` to "guess".

 Dependencies
 ------------
 'git-cvsserver' depends on DBD::SQLite.

 GIT
 ---
 Part of the linkgit:git[1] suite
	git-cvsserver(1)
	================

	NAME
	----
	git-cvsserver - A CVS server emulator for Git

	SYNOPSIS
	--------

	SSH:

	[verse]
	export CVS_SERVER="git cvsserver"
	'cvs' -d :ext:user@server/path/repo.git co <HEAD_name>

	pserver (/etc/inetd.conf):

	[verse]
	cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver

	Usage:

	[verse]
	'git-cvsserver' [options] [pserver\|server] [<directory> ...]

	OPTIONS
	-------

	All these options obviously only make sense if enforced by the server side.
	They have been implemented to resemble the linkgit:git-daemon[1] options as
	closely as possible.

	--base-path <path>::
	Prepend 'path' to requested CVSROOT

	--strict-paths::
	Don't allow recursing into subdirectories

	--export-all::
	Don't check for `gitcvs.enabled` in config. You also have to specify a list
	of allowed directories (see below) if you want to use this option.

	-V::
	--version::
	Print version information and exit

	-h::
	-H::
	--help::
	Print usage information and exit

	<directory>::
	You can specify a list of allowed directories. If no directories
	are given, all are allowed. This is an additional restriction, gitcvs
	access still needs to be enabled by the `gitcvs.enabled` config option
	unless '--export-all' was given, too.


	DESCRIPTION
	-----------

	This application is a CVS emulation layer for Git.

	It is highly functional. However, not all methods are implemented,
	and for those methods that are implemented,
	not all switches are implemented.

	Testing has been done using both the CLI CVS client, and the Eclipse CVS
	plugin. Most functionality works fine with both of these clients.

	LIMITATIONS
	-----------

	CVS clients cannot tag, branch or perform Git merges.

	'git-cvsserver' maps Git branches to CVS modules. This is very different
	from what most CVS users would expect since in CVS modules usually represent
	one or more directories.

	INSTALLATION
	------------

	1. If you are going to offer CVS access via pserver, add a line in
	/etc/inetd.conf like
	+
	--
	------
	cvspserver stream tcp nowait nobody git-cvsserver pserver

	------
	Note: Some inetd servers let you specify the name of the executable
	independently of the value of argv[0] (i.e. the name the program assumes
	it was executed with). In this case the correct line in /etc/inetd.conf
	looks like

	------
	cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver

	------

	Only anonymous access is provided by pserve by default. To commit you
	will have to create pserver accounts, simply add a gitcvs.authdb
	setting in the config file of the repositories you want the cvsserver
	to allow writes to, for example:

	------

	[gitcvs]
	authdb = /etc/cvsserver/passwd

	------
	The format of these files is username followed by the crypted password,
	for example:

	------
	myuser:$1Oyx5r9mdGZ2
	myuser:$1$BA)@$vbnMJMDym7tA32AamXrm./
	------
	You can use the 'htpasswd' facility that comes with Apache to make these
	files, but Apache's MD5 crypt method differs from the one used by most C
	library's crypt() function, so don't use the -m option.

	Alternatively you can produce the password with perl's crypt() operator:
	-----
	perl -e 'my ($user, $pass) = @ARGV; printf "%s:%s\n", $user, crypt($user, $pass)' $USER password
	-----

	Then provide your password via the pserver method, for example:
	------
	cvs -d:pserver:someuser:somepassword <at> server/path/repo.git co <HEAD_name>
	------
	No special setup is needed for SSH access, other than having Git tools
	in the PATH. If you have clients that do not accept the CVS_SERVER
	environment variable, you can rename 'git-cvsserver' to `cvs`.

	Note: Newer CVS versions (>= 1.12.11) also support specifying
	CVS_SERVER directly in CVSROOT like

	------
	cvs -d ":ext;CVS_SERVER=git cvsserver:user@server/path/repo.git" co <HEAD_name>
	------
	This has the advantage that it will be saved in your 'CVS/Root' files and
	you don't need to worry about always setting the correct environment
	variable. SSH users restricted to 'git-shell' don't need to override the default
	with CVS_SERVER (and shouldn't) as 'git-shell' understands `cvs` to mean
	'git-cvsserver' and pretends that the other end runs the real 'cvs' better.
	--
	2. For each repo that you want accessible from CVS you need to edit config in
	the repo and add the following section.
	+
	--
	------
	[gitcvs]
	enabled=1
	# optional for debugging
	logfile=/path/to/logfile

	------
	Note: you need to ensure each user that is going to invoke 'git-cvsserver' has
	write access to the log file and to the database (see
	<<dbbackend,Database Backend>>. If you want to offer write access over
	SSH, the users of course also need write access to the Git repository itself.

	You also need to ensure that each repository is "bare" (without a Git index
	file) for `cvs commit` to work. See linkgit:gitcvs-migration[7].

	[[configaccessmethod]]
	All configuration variables can also be overridden for a specific method of
	access. Valid method names are "ext" (for SSH access) and "pserver". The
	following example configuration would disable pserver access while still
	allowing access over SSH.
	------
	[gitcvs]
	enabled=0

	[gitcvs "ext"]
	enabled=1
	------
	--
	3. If you didn't specify the CVSROOT/CVS_SERVER directly in the checkout command,
	automatically saving it in your 'CVS/Root' files, then you need to set them
	explicitly in your environment. CVSROOT should be set as per normal, but the
	directory should point at the appropriate Git repo. As above, for SSH clients
	_not_ restricted to 'git-shell', CVS_SERVER should be set to 'git-cvsserver'.
	+
	--
	------
	export CVSROOT=:ext:user@server:/var/git/project.git
	export CVS_SERVER="git cvsserver"
	------
	--
	4. For SSH clients that will make commits, make sure their server-side
	.ssh/environment files (or .bashrc, etc., according to their specific shell)
	export appropriate values for GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL,
	GIT_COMMITTER_NAME, and GIT_COMMITTER_EMAIL. For SSH clients whose login
	shell is bash, .bashrc may be a reasonable alternative.

	5. Clients should now be able to check out the project. Use the CVS 'module'
	name to indicate what Git 'head' you want to check out. This also sets the
	name of your newly checked-out directory, unless you tell it otherwise with
	`-d <dir_name>`. For example, this checks out 'master' branch to the
	`project-master` directory:
	+
	------
	cvs co -d project-master master
	------

	[[dbbackend]]
	Database Backend
	----------------

	'git-cvsserver' uses one database per Git head (i.e. CVS module) to
	store information about the repository to maintain consistent
	CVS revision numbers. The database needs to be
	updated (i.e. written to) after every commit.

	If the commit is done directly by using `git` (as opposed to
	using 'git-cvsserver') the update will need to happen on the
	next repository access by 'git-cvsserver', independent of
	access method and requested operation.

	That means that even if you offer only read access (e.g. by using
	the pserver method), 'git-cvsserver' should have write access to
	the database to work reliably (otherwise you need to make sure
	that the database is up-to-date any time 'git-cvsserver' is executed).

	By default it uses SQLite databases in the Git directory, named
	`gitcvs.<module_name>.sqlite`. Note that the SQLite backend creates
	temporary files in the same directory as the database file on
	write so it might not be enough to grant the users using
	'git-cvsserver' write access to the database file without granting
	them write access to the directory, too.

	The database can not be reliably regenerated in a
	consistent form after the branch it is tracking has changed.
	Example: For merged branches, 'git-cvsserver' only tracks
	one branch of development, and after a 'git merge' an
	incrementally updated database may track a different branch
	than a database regenerated from scratch, causing inconsistent
	CVS revision numbers. `git-cvsserver` has no way of knowing which
	branch it would have picked if it had been run incrementally
	pre-merge. So if you have to fully or partially (from old
	backup) regenerate the database, you should be suspicious
	of pre-existing CVS sandboxes.

	You can configure the database backend with the following
	configuration variables:

	Configuring database backend
	~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	'git-cvsserver' uses the Perl DBI module. Please also read
	its documentation if changing these variables, especially
	about `DBI->connect()`.

	gitcvs.dbname::
	Database name. The exact meaning depends on the
	selected database driver, for SQLite this is a filename.
	Supports variable substitution (see below). May
	not contain semicolons (`;`).
	Default: '%Ggitcvs.%m.sqlite'

	gitcvs.dbdriver::
	Used DBI driver. You can specify any available driver
	for this here, but it might not work. cvsserver is tested
	with 'DBD::SQLite', reported to work with
	'DBD::Pg', and reported not to work with 'DBD::mysql'.
	Please regard this as an experimental feature. May not
	contain colons (`:`).
	Default: 'SQLite'

	gitcvs.dbuser::
	Database user. Only useful if setting `dbdriver`, since
	SQLite has no concept of database users. Supports variable
	substitution (see below).

	gitcvs.dbpass::
	Database password. Only useful if setting `dbdriver`, since
	SQLite has no concept of database passwords.

	gitcvs.dbTableNamePrefix::
	Database table name prefix. Supports variable substitution
	(see below). Any non-alphabetic characters will be replaced
	with underscores.

	All variables can also be set per access method, see <<configaccessmethod,above>>.

	Variable substitution
	^^^^^^^^^^^^^^^^^^^^^
	In `dbdriver` and `dbuser` you can use the following variables:

	%G::
	Git directory name
	%g::
	Git directory name, where all characters except for
	alpha-numeric ones, `.`, and `-` are replaced with
	`_` (this should make it easier to use the directory
	name in a filename if wanted)
	%m::
	CVS module/Git head name
	%a::
	access method (one of "ext" or "pserver")
	%u::
	Name of the user running 'git-cvsserver'.
	If no name can be determined, the
	numeric uid is used.

	ENVIRONMENT
	-----------

	These variables obviate the need for command-line options in some
	circumstances, allowing easier restricted usage through git-shell.

	GIT_CVSSERVER_BASE_PATH takes the place of the argument to --base-path.

	GIT_CVSSERVER_ROOT specifies a single-directory whitelist. The
	repository must still be configured to allow access through
	git-cvsserver, as described above.

	When these environment variables are set, the corresponding
	command-line arguments may not be used.

	Eclipse CVS Client Notes
	------------------------

	To get a checkout with the Eclipse CVS client:

	1. Select "Create a new project -> From CVS checkout"
	2. Create a new location. See the notes below for details on how to choose the
	right protocol.
	3. Browse the 'modules' available. It will give you a list of the heads in
	the repository. You will not be able to browse the tree from there. Only
	the heads.
	4. Pick 'HEAD' when it asks what branch/tag to check out. Untick the
	"launch commit wizard" to avoid committing the .project file.

	Protocol notes: If you are using anonymous access via pserver, just select that.
	Those using SSH access should choose the 'ext' protocol, and configure 'ext'
	access on the Preferences->Team->CVS->ExtConnection pane. Set CVS_SERVER to
	"`git cvsserver`". Note that password support is not good when using 'ext',
	you will definitely want to have SSH keys setup.

	Alternatively, you can just use the non-standard extssh protocol that Eclipse
	offer. In that case CVS_SERVER is ignored, and you will have to replace
	the cvs utility on the server with 'git-cvsserver' or manipulate your `.bashrc`
	so that calling 'cvs' effectively calls 'git-cvsserver'.

	Clients known to work
	---------------------

	- CVS 1.12.9 on Debian
	- CVS 1.11.17 on MacOSX (from Fink package)
	- Eclipse 3.0, 3.1.2 on MacOSX (see Eclipse CVS Client Notes)
	- TortoiseCVS

	Operations supported
	--------------------

	All the operations required for normal use are supported, including
	checkout, diff, status, update, log, add, remove, commit.

	Most CVS command arguments that read CVS tags or revision numbers
	(typically -r) work, and also support any git refspec
	(tag, branch, commit ID, etc).
	However, CVS revision numbers for non-default branches are not well
	emulated, and cvs log does not show tags or branches at
	all. (Non-main-branch CVS revision numbers superficially resemble CVS
	revision numbers, but they actually encode a git commit ID directly,
	rather than represent the number of revisions since the branch point.)

	Note that there are two ways to checkout a particular branch.
	As described elsewhere on this page, the "module" parameter
	of cvs checkout is interpreted as a branch name, and it becomes
	the main branch. It remains the main branch for a given sandbox
	even if you temporarily make another branch sticky with
	cvs update -r. Alternatively, the -r argument can indicate
	some other branch to actually checkout, even though the module
	is still the "main" branch. Tradeoffs (as currently
	implemented): Each new "module" creates a new database on disk with
	a history for the given module, and after the database is created,
	operations against that main branch are fast. Or alternatively,
	-r doesn't take any extra disk space, but may be significantly slower for
	many operations, like cvs update.

	If you want to refer to a git refspec that has characters that are
	not allowed by CVS, you have two options. First, it may just work
	to supply the git refspec directly to the appropriate CVS -r argument;
	some CVS clients don't seem to do much sanity checking of the argument.
	Second, if that fails, you can use a special character escape mechanism
	that only uses characters that are valid in CVS tags. A sequence
	of 4 or 5 characters of the form (underscore (`"_"`), dash (`"-"`),
	one or two characters, and dash (`"-"`)) can encode various characters based
	on the one or two letters: `"s"` for slash (`"/"`), `"p"` for
	period (`"."`), `"u"` for underscore (`"_"`), or two hexadecimal digits
	for any byte value at all (typically an ASCII number, or perhaps a part
	of a UTF-8 encoded character).

	Legacy monitoring operations are not supported (edit, watch and related).
	Exports and tagging (tags and branches) are not supported at this stage.

	CRLF Line Ending Conversions
	~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	By default the server leaves the '-k' mode blank for all files,
	which causes the CVS client to treat them as a text files, subject
	to end-of-line conversion on some platforms.

	You can make the server use the end-of-line conversion attributes to
	set the '-k' modes for files by setting the `gitcvs.usecrlfattr`
	config variable. See linkgit:gitattributes[5] for more information
	about end-of-line conversion.

	Alternatively, if `gitcvs.usecrlfattr` config is not enabled
	or the attributes do not allow automatic detection for a filename, then
	the server uses the `gitcvs.allbinary` config for the default setting.
	If `gitcvs.allbinary` is set, then file not otherwise
	specified will default to '-kb' mode. Otherwise the '-k' mode
	is left blank. But if `gitcvs.allbinary` is set to "guess", then
	the correct '-k' mode will be guessed based on the contents of
	the file.

	For best consistency with 'cvs', it is probably best to override the
	defaults by setting `gitcvs.usecrlfattr` to true,
	and `gitcvs.allbinary` to "guess".

	Dependencies
	------------
	'git-cvsserver' depends on DBD::SQLite.

	GIT
	---
	Part of the linkgit:git[1] suite