/usr/bin/opam

NAME
       opam - source-based package management

SYNOPSIS
       opam [COMMAND] …

DESCRIPTION
       Opam is a package manager. It uses the powerful mancoosi tools to
       handle dependencies, including support for version constraints,
       optional dependencies, and conflict management. The default
       configuration binds it to the official package repository for OCaml.

       It has support for different remote repositories such as HTTP, rsync,
       git, darcs and mercurial. Everything is installed within a local opam
       directory, that can include multiple installation prefixes with
       different sets of installed packages.

       Use either opam <command> --help or opam help <command> for more
       information on a specific command.

COMMANDS
       admin [OPTION]…
           Tools for repository administrators

       clean [OPTION]…
           Cleans up opam caches

       config [OPTION]… [COMMAND] [ARG]…
           Display configuration options for packages.

       env [OPTION]…
           Prints appropriate shell variable assignments to stdout

       exec [OPTION]… COMMAND [ARG]...…
           Executes a command in the proper opam environment

       help [--man-format=FMT] [OPTION]… [TOPIC]
           Display help about opam and opam commands.

       init [OPTION]… [NAME] [ADDRESS]
           Initialize opam state, or set init options.

       install [OPTION]… [PACKAGES]…
           Install a list of packages.

       lint [OPTION]… [FILES]…
           Checks and validate package description ('opam') files.

       list [--check] [--no-depexts] [--silent] [OPTION]… [PATTERNS]…
           Display the list of available packages.

       lock [--direct-only] [--keep-local] [--lock-suffix=SUFFIX] [OPTION]…
       [PACKAGES]…
           Create locked opam files to share build environments across hosts.

       option [--global] [OPTION]… [FIELD[(=|+=|-=)[VALUE]]]
           Global and switch configuration options settings

       pin [OPTION]… [COMMAND] [ARG]…
           Pin a given package to a specific version or source.

       reinstall [OPTION]… [PACKAGES]…
           Reinstall a list of packages.

       remove [OPTION]… [PACKAGES]…
           Remove a list of packages.

       repository [--kind=KIND] [--rank=RANK] [--short] [OPTION]… [COMMAND]
       [ARG]…
           Manage opam repositories.

       show [OPTION]… [PACKAGES]…
           Display information about specific packages.

       source [OPTION]… PACKAGE
           Get the source of an opam package.

       switch [OPTION]… [COMMAND] [ARG]…
           Manage multiple installation prefixes.

       tree [--recursive] [--subpath=PATH] [OPTION]… [PACKAGES]…
           Draw the dependency forest of installed packages.

       update [OPTION]… [NAMES]…
           Update the list of available packages.

       upgrade [OPTION]… [PACKAGES]…
           Upgrade the installed package to latest version.

       var [--global] [--package=PACKAGE] [OPTION]… [VAR[=[VALUE]]]
           Display and update the value associated with a given variable

COMMAND ALIASES
       info [OPTION]… [PACKAGES]…
           An alias for show.

       remote [--kind=KIND] [--rank=RANK] [--short] [OPTION]… [COMMAND]
       [ARG]…
           An alias for repository.

       search [--check] [--no-depexts] [--silent] [OPTION]… [PATTERNS]…
           An alias for list --search.

       uninstall [OPTION]… [PACKAGES]…
           An alias for remove.

       unpin [OPTION]… [ARG]…
           An alias for pin remove.

       why [--recursive] [--subpath=PATH] [OPTION]… [PACKAGES]…
           An alias for tree --rev-deps.

COMMON OPTIONS
       These options are common to all commands.

       --best-effort
           Don't fail if all requested packages can't be installed: try to
           install as many as possible. Note that not all external solvers
           may support this option (recent versions of aspcud or mccs
           should). This is equivalent to setting $OPAMBESTEFFORT environment
           variable.

       --cli=MAJOR.MINOR (absent=2.6)
           Use the command-line interface syntax and semantics of
           MAJOR.MINOR. Intended for any persistent use of opam (scripts,
           blog posts, etc.), any version of opam in the same MAJOR series
           will behave as for the specified MINOR release. The flag was not
           available in opam 2.0, so to select the 2.0 CLI, set the OPAMCLI
           environment variable to 2.0 instead of using this parameter.

       --color=WHEN
           Colorize the output. WHEN must be one of always, never or auto.

       --confirm-level=LEVEL
           Confirmation level, LEVEL must be one of ask, no, yes or
           unsafe-yes. Can be specified more than once. If --yes or --no are
           also given, the value of the last --confirm-level is taken into
           account. This is equivalent to setting $OPAMCONFIRMLEVEL`.

       --criteria=CRITERIA
           Specify user preferences for dependency solving for this run.
           Overrides $OPAMCRITERIA, $OPAMFIXUPCRITERIA and
           $OPAMUPGRADECRITERIA. For details on the supported language, and
           the external solvers available, see
           http://opam.ocaml.org/doc/External_solvers.html. A general guide
           to using solver preferences can be found at
           http://www.dicosmo.org/Articles/usercriteria.pdf.

       --cudf=FILENAME
           Debug option: Save the CUDF requests sent to the solver to
           FILENAME-<n>.cudf where <n> is the n-th call to the solver during
           the opam run.

       --debug
           Print debug message to stderr. This is equivalent to setting
           $OPAMDEBUG to "true".

       --debug-level=LEVEL
           Like --debug, but allows specifying the debug level (--debug sets
           it to 1). Equivalent to setting $OPAMDEBUG to a positive integer.

       --git-version
           Print the git version of opam, if set (i.e. you are using a
           development version), and exit.

       --help[=FMT] (default=auto)
           Show this help in format FMT. The value FMT must be one of auto,
           pager, groff or plain. With auto, the format is pager or plain
           whenever the TERM env var is dumb or undefined.

       --ignore-pin-depends
           Ignore extra pins required by packages that get pinned, either
           manually through opam pin or through opam install DIR. This is
           equivalent to setting IGNOREPINDEPENDS=true.

       --json=FILENAME
           Save the results of the opam run in a computer-readable file. If
           the filename contains the character `%', it will be replaced by an
           index that doesn't overwrite an existing file. Similar to setting
           the $OPAMJSON variable.

       --no
           Answer no to all opam yes/no questions without prompting. See also
           --confirm-level. This is equivalent to setting $OPAMNO to "true".

       --no-aspcud
           Removed in 2.1.

       --no-auto-upgrade
           When configuring or updating a repository that is written for an
           earlier opam version (1.2), opam internally converts it to the
           current format. This disables this behaviour. Note that
           repositories should define their format version in a 'repo' file
           at their root, or they will be assumed to be in the older format.
           It is, in any case, preferable to upgrade the repositories
           manually using opam admin upgrade [--mirror URL] when possible.

       --no-self-upgrade
           Opam will replace itself with a newer binary found at
           OPAMROOT/opam if present. This disables this behaviour.

       -q, --quiet
           Disables --verbose.

       --root=ROOT
           Use ROOT as the current root path. This is equivalent to setting
           $OPAMROOT to ROOT.

       --safe, --readonly
           Make sure nothing will be automatically updated or rewritten.
           Useful for calling from completion scripts, for example. Will fail
           whenever such an operation is needed ; also avoids waiting for
           locks, skips interactive questions and overrides the $OPAMDEBUG
           variable. This is equivalent to set environment variable
           $OPAMSAFE.

       --solver=CMD
           Specify the CUDF solver to use for resolving package installation
           problems. This is either a predefined solver (this version of opam
           supports builtin-mccs+lp(), builtin-mccs+glpk,
           builtin-dummy-z3-solver, builtin-0install, aspcud, mccs,
           aspcud-old, packup), or a custom command that should contain the
           variables %{input}%, %{output}%, %{criteria}%, and optionally
           %{timeout}%. This is equivalent to setting $OPAMEXTERNALSOLVER.

       --strict
           Fail whenever an error is found in a package definition or a
           configuration file. The default is to continue silently if
           possible.

       --switch=SWITCH
           Use SWITCH as the current compiler switch. This is equivalent to
           setting $OPAMSWITCH to SWITCH.

       --use-internal-solver
           Disable any external solver, and use the built-in one (this
           requires that opam has been compiled with a built-in solver). This
           is equivalent to setting $OPAMNOASPCUD or $OPAMUSEINTERNALSOLVER.

       -v, --verbose
           Be more verbose. One -v shows all package commands, repeat to also
           display commands called internally (e.g. tar, curl, patch etc.)
           Repeating n times is equivalent to setting $OPAMVERBOSE to "n".

       --version
           Show version information.

       -w, --working-dir
           Whenever updating packages that are bound to a local,
           version-controlled directory, update to the current working state
           of their source instead of the last committed state, or the ref
           they are pointing to. As source directory is copied as it is, if
           it isn't clean it may result on a opam build failure. This only
           affects packages explicitly listed on the command-line. It can
           also be set with $OPAMWORKINGDIR.

       -y, --yes
           Answer yes to all opam yes/no questions without prompting. See
           also --confirm-level. This is equivalent to setting $OPAMYES to
           "true".

ENVIRONMENT
       Opam makes use of the environment variables listed here. Boolean
       variables should be set to "0", "no", "false" or the empty string to
       disable, "1", "yes" or "true" to enable.

       OPAMALLPARENS surround all filters with parenthesis.

       OPAMASSUMEDEPEXTS see option `--assume-depexts'.

       OPAMAUTOANSWER internal use only.

       OPAMAUTOREMOVE see remove option `--auto-remove'.

       OPAMBESTEFFORT see option `--best-effort'.

       OPAMBESTEFFORTPREFIXCRITERIA sets the string that must be prepended to
       the criteria when the `--best-effort' option is set, and is expected
       to maximise the `opam-query' property in the solution.

       OPAMBUILDDOC Removed in 2.1.

       OPAMBUILDTEST Removed in 2.1.

       OPAMCLI see option `--cli'.

       OPAMCOLOR when set to always or never, sets a default value for the
       `--color' option.

       OPAMCONFIRMLEVEL see option `--confirm-level`. OPAMCONFIRMLEVEL has
       priority over OPAMYES and OPAMNO.

       OPAMCRITERIA specifies user preferences for dependency solving. The
       default value depends on the solver version, use `config report' to
       know the current setting. See also option --criteria.

       OPAMCUDFFILE save the cudf graph to file-actions-explicit.dot.

       OPAMCUDFTRIM controls the filtering of unrelated packages during CUDF
       preprocessing.

       OPAMCURL can be used to select a given 'curl' program. See OPAMFETCH
       for more options.

       OPAMDEBUG see options `--debug' and `--debug-level'.

       OPAMDEBUGSECTIONS if set, limits debug messages to the space-separated
       list of sections. Sections can optionally have a specific debug level
       (for example, CLIENT:2 or CLIENT CUDF:2), but otherwise use
       `--debug-level'.

       OPAMDIGDEPTH defines how aggressive the lookup for conflicts during
       CUDF preprocessing is.

       OPAMDOWNLOADJOBS sets the maximum number of simultaneous downloads.

       OPAMDROPWORKINGDIR overrides packages previously updated with
       --working-dir on update. Without this variable set, opam would keep
       them unchanged unless explicitly named on the command-line.

       OPAMDRYRUN see option `--dry-run'.

       OPAMEDITOR sets the editor to use for opam file editing, overrides
       $EDITOR and $VISUAL.

       OPAMERRLOGLEN sets the number of log lines printed when a sub-process
       fails. 0 to print all.

       OPAMEXTERNALSOLVER see option `--solver'.

       OPAMFAKE see option `--fake'.

       OPAMFETCH specifies how to download files: either `wget', `curl' or a
       custom command where variables %{url}%, %{out}%, %{retry}%,
       %{compress}% and %{checksum}% will be replaced. Overrides the
       'download-command' value from the main config file.

       OPAMFIXUPCRITERIA same as OPAMUPGRADECRITERIA, but specific to fixup
       and reinstall.

       OPAMIGNOREAVAILABLE see install option `--ignore-available-on'.

       OPAMIGNORECONSTRAINTS see install option `--ignore-constraints-on'.

       OPAMIGNOREPINDEPENDS see option `--ignore-pin-depends'.

       OPAMINPLACEBUILD see option `--inplace-build'.

       OPAMJOBS sets the maximum number of parallel workers to run.

       OPAMJSON log json output to the given file (use character `%' to index
       the files).

       OPAMKEEPBUILDDIR see install option `--keep-build-dir'.

       OPAMKEEPLOGS tells opam to not remove some temporary command logs and
       some backups. This skips some finalisers and may also help to get more
       reliable backtraces.

       OPAMLOCKED combination of `--locked' and `--lock-suffix' options.

       OPAMLOGS logdir sets log directory, default is a temporary directory
       in /tmp

       OPAMMAKECMD set the system make command to use.

       OPAMMERGEOUT merge process outputs, stderr on stdout.

       OPAMNO answer no to any question asked, see options `--no` and
       `--confirm-level`. OPAMNO is ignored if either OPAMCONFIRMLEVEL or
       OPAMYES is set.

       OPAMNOAGGREGATE with `opam admin check', don't aggregate packages.

       OPAMNOASPCUD Deprecated.

       OPAMNOAUTOUPGRADE disables automatic internal upgrade of repositories
       in an earlier format to the current one, on 'update' or 'init'.

       OPAMNOCHECKSUMS enables option --no-checksums when available.

       OPAMNODEPEXTS disables system dependencies handling, see option
       `--no-depexts'.

       OPAMNOENVNOTICE Internal.

       OPAMNOSELFUPGRADE see option `--no-self-upgrade'

       OPAMPINKINDAUTO sets whether version control systems should be
       detected when pinning to a local path. Enabled by default since 1.3.0.

       OPAMPRECISETRACKING fine grain tracking of directories.

       OPAMPREPRO set this to false to disable CUDF preprocessing. Less
       efficient, but might help debugging solver issue.

       OPAMREPOSITORYTARRING internally store all non-vcs repositories as
       tar.gz files (by default, http repositories are stored as archive).
       This can be much faster on filesystems that don't cope well with
       scanning large trees. All operation are done in-memory, no I/O for
       scanning the repository.

       OPAMREQUIRECHECKSUMS Enables option `--require-checksums' when
       available (e.g. for `opam install').

       OPAMRETRIES sets the number of tries before failing downloads.

       OPAMREUSEBUILDDIR see option `--reuse-build-dir'.

       OPAMROOT see option `--root'. This is automatically set by `opam env
       --root=DIR --set-root'.

       OPAMROOTISOK don't complain when running as root.

       OPAMSAFE see option `--safe'.

       OPAMSHOW see option `--show'.

       OPAMSKIPUPDATE see option `--skip-updates'.

       OPAMSKIPVERSIONCHECKS bypasses some version checks. Unsafe, for
       compatibility testing only.

       OPAMSOLVERALLOWSUBOPTIMAL (default `true') allows some solvers to
       still return a solution when they reach timeout; while the solution
       remains assured to be consistent, there is no guarantee in this case
       that it fits the expected optimisation criteria. If `true', opam
       willcontinue with a warning, if `false' a timeout is an error.
       Currently only the builtin-z3 backend handles this degraded case.

       OPAMSOLVERTIMEOUT change the time allowance of the solver. Default is
       60.0, set to 0 for unlimited. Note that all solvers may not support
       this option.

       OPAMSOLVERTOLERANCE changes the tolerance towards the solver choosing
       an unoptimized solution (i.e. might pull outdated packages). Typical
       values range from 0.0 (best solution known to the solver) to 1.0
       (unoptimized solution). Default is 0.0. This option is useful in case
       the solver can't find a solution in a reasonable time (see
       $OPAMSOLVERTIMEOUT). Note that all solvers may not support this
       option.

       OPAMSTATS Removed in 2.4.

       OPAMSTATUSLINE display a dynamic status line showing what's currently
       going on on the terminal. (one of one of always, never or auto)

       OPAMSTRICT fail on inconsistencies (file reading, switch import,
       etc.).

       OPAMSWITCH see option `--switch'. Automatically set by `opam env
       --switch=SWITCH --set-switch'.

       OPAMUNLOCKBASE see install option `--unlock-base'.

       OPAMUPGRADECRITERIA specifies user preferences for dependency solving
       when performing an upgrade. Overrides OPAMCRITERIA in upgrades if both
       are set. See also option --criteria.

       OPAMUSEINTERNALSOLVER see option `--use-internal-solver'.

       OPAMUSEOPENSSL Removed in 2.2.

       OPAMUTF8 use UTF8 characters in output (one of one of always, never or
       auto). By default `auto', which is determined from the locale).

       OPAMUTF8MSGS use extended UTF8 characters (camels) in opam messages.
       Implies OPAMUTF8. This is set by default on macOS only.

       OPAMVALIDATIONHOOK if set, uses the `%{hook%}' command to validate an
       opam repository update.

       OPAMVERBOSE see option `--verbose'.

       OPAMVERBOSEON see option --verbose-on

       OPAMVERSIONLAGPOWER do not use.

       OPAMWITHDEVSETUP see install option `--with-dev-setup'.

       OPAMWITHDOC see install option `--with-doc'.

       OPAMWITHTEST see install option `--with-test.

       OPAMWORKINGDIR see option `--working-dir'.

       OPAMYES see options `--yes' and `--confirm-level`. OPAMYES has
       priority over OPAMNO and is ignored if OPAMCONFIRMLEVEL is set.

       OPAMVAR_var overrides the contents of the variable var when
       substituting `%{var}%` strings in `opam` files.

       OPAMVAR_package_var overrides the contents of the variable package:var
       when substituting `%{package:var}%` strings in `opam` files.

CLI VERSION
       All scripts and programmatic invocations of opam should use `--cli' in
       order to ensure that they work seamlessly with future versions of the
       opam client. Additionally, blog posts or other documentation can
       benefit, as it prevents information from becoming stale.

       Although opam only supports roots (~/.opam/) for the current version,
       it does provide backwards compatibility for its command-line
       interface.

       Since CLI version support was only added in opam 2.1, use OPAMCLI to
       select 2.0 support (as opam 2.0 will just ignore it), and `--cli=2.1'
       for 2.1 (or later) versions, since an environment variable controlling
       the parsing of syntax is brittle. To this end, opam displays a warning
       if OPAMCLI specifies a valid version other than 2.0, and also if
       `--cli=2.0' is specified.

       The command-line version is selected by using the `--cli' option or
       the OPAMCLI environment variable. `--cli' may be specified morethan
       once, where the last instance takes precedence. OPAMCLI is only
       inspected if `--cli' is not given.

EXIT STATUS
       As an exception to the following, the `exec' command returns 127 if
       the command was not found or couldn't be executed, and the command's
       exit value otherwise.

       0   Success, or true for boolean queries.

       1   False. Returned when a boolean return value is expected, e.g. when
           running with --check, or for queries like opam lint.

       2   Bad command-line arguments, or command-line arguments pointing to
           an invalid context (e.g. file not following the expected format).

       5   Not found. You requested something (package, version, repository,
           etc.) that couldn't be found.

       10  Aborted. The operation required confirmation, which wasn't given.

       15  Could not acquire the locks required for the operation.

       20  There is no solution to the user request. This can be caused by
           asking to install two incompatible packages, for example.

       30  Error in package definition, or other metadata files. Using
           --strict raises this error more often.

       31  Package script error. Some package operations were unsuccessful.
           This may be an error in the packages or an incompatibility with
           your system. This can be a partial error.

       40  Sync error. Could not fetch some remotes from the network. This
           can be a partial error.

       50  Configuration error. Opam or system configuration doesn't allow
           operation, and needs fixing.

       60  Solver failure. The solver failed to return a sound answer. It can
           be due to a broken external solver, or an error in solver
           configuration.

       99  Internal error. Something went wrong, likely due to a bug in opam
           itself.

       130 User interrupt. SIGINT was received, generally due to the user
           pressing Ctrl-C.

       0   on success.

       123 on indiscriminate errors reported on standard error.

       124 on command line parsing errors.

       125 on unexpected internal errors (bugs).

FURTHER DOCUMENTATION
       See https://opam.ocaml.org/doc.

AUTHORS
       David Allsopp <david@tarides.com>
       Vincent Bernardoff <vb@luminar.eu.org>
       Raja Boujbel <raja.boujbel@ocamlpro.com>
       Kate Deplaix <kit-ty-kate@exn.st>
       Roberto Di Cosmo <roberto@dicosmo.org>
       Thomas Gazagnaire <thomas@gazagnaire.org>
       Louis Gesbert <louis.gesbert@ocamlpro.com>
       Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>
       Anil Madhavapeddy <anil@recoil.org>
       Guillem Rieu <guillem.rieu@ocamlpro.com>
       Ralf Treinen <ralf.treinen@pps.jussieu.fr>
       Frederic Tuong <tuong@users.gforge.inria.fr>

BUGS
       Check bug reports at https://github.com/ocaml/opam/issues.