OPAM-SWITCH(1) Opam Manual OPAM-SWITCH(1)NAMEopam-switch - Manage multiple installation of compilers.
SYNOPSIS
opam switch [OPTION]... [COMMAND] [ARG]...
DESCRIPTION
This command allows one to switch between different compiler versions,
installing the compiler if opam switch is used to switch to that
compiler for the first time. The different compiler versions are
totally independent from each other, meaning that OPAM maintains a
separate state (e.g. list of installed packages...) for each.
See the documentation of opam switch list to see the compilers which
are available, and how to switch or to install a new one.
COMMANDS
Without argument, defaults to list.
SWITCH
With a SWITCH argument, defaults to set SWITCH.
install SWITCH
Install the given compiler. The command fails if the switch is
already installed (e.g. it will not transparently switch to the
installed compiler switch, as with set).
set SWITCH
Set the currently active switch, installing it if needed.
remove SWITCH
Remove the given compiler.
export FILE
Save the current switch state to a file.
import FILE
Import a saved switch state.
reinstall SWITCH
Reinstall the given compiler switch. This will also reinstall all
packages.
list
List compilers. By default, lists installed and `standard'
compilers. Use `--all' to get the list of all installable
compilers. The first column displays the switch name (if any), the
second one the switch state (C = current, I = installed, -- = not
installed), the third one the compiler name and the last one the
compiler description. To switch to an already installed compiler
alias (with state = I), use opam switch <name>. If you want to use
a new compiler <comp>, use opam switch <comp>: this will download,
compile and create a fresh and independent environment where new
packages can be installed. If you want to create a new compiler
alias (for instance because you already have this compiler version
installed), use opam switch <name> --alias-of <comp>. In case
<name> and <comp> are the same, this is equivalent to opam switch
<comp>.
show
Show the current compiler.
OPTIONS-A COMP, --alias-of=COMP
The name of the compiler description which will be aliased.
-a, --all
List all the compilers which can be installed on the system.
-b, --keep-build-dir
Keep the build directory. This is equivalent to setting
$OPAMKEEPBUILDDIR to "true".
-d, --build-doc
Build the package documentation. This is equivalent to setting
$OPAMBUILDDOC to "true".
--dry-run
Simulate the command, but don't actually perform any changes.
-e TAGS, --external=TAGS
Display the external packages associated to the given tags. This is
deprecated, use `opam list --external' instead
--fake
This option registers the actions into the OPAM database, without
actually performing them. WARNING: This option is dangerous and
likely to break your OPAM environment. You probably want
`--dry-run'. You've been warned.
-i, --installed
List installed compiler switches only.
-j JOBS, --jobs=JOBS
Set the maximal number of concurrent jobs to use. You can also set
it using the $OPAMJOBS environment variable.
--json=FILENAME
Save the result output of an OPAM run in a computer-readable file
-m MAKE, --make=MAKE
Use MAKE as the default 'make' command.
--no-checksums
Do not verify the checksum of downloaded archives.This is
equivalent to setting $OPAMNOCHECKSUMS to "true".
--no-switch
Only install the compiler switch, without switching to it. If the
compiler switch is already installed, then do nothing.
--no-warning
Do not display any warning related to environment variables.
--require-checksums
Reject the installation of packages that don't provide a checksum
for the upstream archives. This is equivalent to setting
$OPAMREQUIRECHECKSUMS to "true".
-s, --short
Output raw lists of names, one per line, skipping any details.
--show-actions
Call the solver and display the actions. Don't perform any changes.
-t, --build-test
Build and run the package unit-tests. This is equivalent to setting
$OPAMBUILDTEST to "true".
COMMON OPTIONS
These options are common to all commands.
--color=WHEN (absent=auto)
Colorize the output. WHEN must be one of `always', `never' or
`auto'.
--criteria=CRITERIA
Specify user preferences for dependency solving for this run.
Overrides both $OPAMCRITERIA and $OPAMUPGRADECRITERIA. For details
on the supported language, and the external solvers available, see
http://opam.ocaml.org/doc/Specifying_Solver_Preferences.html. A
general guide to using solver preferences can be found at
http://www.dicosmo.org/Articles/usercriteria.pdf. The default value
is
-count(down),-count(removed),-notuptodate(solution),-sum(solution,version-lag),-count(new)
for upgrades, and
-count(removed),-notuptodate(request),-sum(request,version-lag),-count(down),-notuptodate(changed),-count(changed),-notuptodate(solution),-sum(solution,version-lag)
otherwise.
--cudf=FILENAME
Debug option: Save the CUDF requests sent to the solver to
FILENAME-<n>.cudf.
--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 if it exists and exit.
--help[=FMT] (default=pager)
Show this help in format FMT (pager, plain or groff).
--no-base-packages
Do not install base packages (useful for testing purposes). This is
equivalent to setting $OPAMNOBASEPACKAGES to a non-empty string.
--no-self-upgrade
OPAM will replace itself with a newer binary found at OPAMROOT/opam
if present. This disables this behaviour.
-q, --quiet
Be quiet when installing a new compiler.
--root=ROOT (absent=~/.opam)
Use ROOT as the current root path. This is equivalent to setting
$OPAMROOT to ROOT.
--safe
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.
--solver=CMD
Specify the name of the external dependency solver. The default
value is aspcud. Either 'aspcud', 'packup' or a custom command that
may contain the variables %{input}%, %{output}% and %{criteria}%
--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, --no-aspcud
Force use of internal heuristics, even if an external solver is
available.
-v, --verbose
Be more verbose, show package sub-commands and their output. Repeat
to see more. Repeating n times is equivalent to setting
$OPAMVERBOSE to "n".
--version
Show version information.
-y, --yes
Disable interactive mode and answer yes to all questions that would
otherwise be asked to the user. This is equivalent to setting
$OPAMYES to "true".
ENVIRONMENT VARIABLES
OPAM makes use of the environment variables listed here. Boolean
variables should be set to "0", "no" of "false" to disable, "1", "yes"
or "true" to enable.
OPAMCOLOR, when set to always or never, sets a default value for the
--color option.
OPAMCRITERIA specifies user preferences for dependency solving.The
default value is
-count(removed),-notuptodate(request),-sum(request,version-lag),-count(down),-notuptodate(changed),-count(changed),-notuptodate(solution),-sum(solution,version-lag).
See also option --criteria
OPAMCURL can be used to select a given 'curl' program. See OPAMFETCH
for more options.
OPAMDEBUG see options `--debug' and `--debug-level'.
OPAMDOWNLOADJOBS sets the maximum number of simultaneous downloads.
OPAMEXTERNALSOLVER see option `--solver'.
OPAMFETCH specifies how to download files: either `wget', `curl' or a
custom command where variables %{url}%, %{out}%, %{retries}%,
%{compress}% and %{checksum}% will be replaced. Overrides the
'download-command' value from the main config file.
OPAMJOBS sets the maximum number of parallel workers to run.
OPAMLOCKRETRIES sets the number of tries after which OPAM gives up
acquiring its lock and fails. <= 0 means infinite wait.
OPAMNO answer no to any question asked.
OPAMNOASPCUD see option `--no-aspcud'.
OPAMNOSELFUPGRADE see option `--no-self-upgrade'.
OPAMPINKINDAUTO if set, version control systems are detected when
pinning to a local path.
OPAMREQUIRECHECKSUMS see option `--require-checksums'.
OPAMRETRY sets the number of tries before failing downloads.
OPAMROOT see option `--root'. This is automatically set by `opam config
env --root=DIR' when DIR is non-default or OPAMROOT is already defined.
OPAMSAFE see option `--safe'
OPAMSKIPVERSIONCHECKS bypasses some version checks. Unsafe, for
compatibility testing only.
OPAMSOLVERTIMEOUT change the time allowance of the internal solver.
OPAMSTATUSLINE display a dynamic status line showing what's currently
going on on the terminal. (one of one of `always', `never' or `auto')
OPAMSWITCH see option `--switch'. Automatically set by `opam config env
--switch=SWITCH'.
OPAMUPGRADECRITERIA specifies user preferences for dependency solving
when performing an upgrade. Overrides OPAMCRITERIA in upgrades if both
are set.The default value is
-count(down),-count(removed),-notuptodate(solution),-sum(solution,version-lag),-count(new).
See also option --criteria
OPAMUSEINTERNALSOLVER see option `--use-internal-solver'.
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 OSX only.
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.
OPAMVERBOSE see option `--verbose'.
OPAMYES see option `--yes'.
FURTHER DOCUMENTATION
See https://opam.ocaml.org.
AUTHORS
Thomas Gazagnaire <thomas@gazagnaire.org>
Anil Madhavapeddy <anil@recoil.org>
Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>
Frederic Tuong <tuong@users.gforge.inria.fr>
Louis Gesbert <louis.gesbert@ocamlpro.com>
Vincent Bernardoff <vb@luminar.eu.org>
Guillem Rieu <guillem.rieu@ocamlpro.com>
Roberto Di Cosmo <roberto@dicosmo.org>
BUGS
Check bug reports at https://github.com/ocaml/opam/issues.
Opam 1.2.2OPAM-SWITCH(1)
