1OPAM-VAR(1)                       Opam Manual                      OPAM-VAR(1)
2
3
4

NAME

6       opam-var - Display and update the value associated with a given
7       variable
8

SYNOPSIS

10       opam var [OPTION]… [VAR[=[VALUE]]]
11

DESCRIPTION

13       Without argument, lists the opam variables currently defined. With a
14       VAR argument, prints the value associated with VAR. Otherwise, sets or
15       updates VAR's value. If no scope is given, it acts on switch variables
16       by default. This command does not perform any variable expansion.
17

ARGUMENTS

19       VAR[=[VALUE]]
20           If only VAR is given, displays its associated value. If VALUE is
21           absent, VAR's value is removed. Otherwise, its value is
22           overwritten.
23

OPTIONS

25       --global
26           Act on global configuration
27
28       --no
29           Answer no to all opam yes/no questions without prompting. See also
30           --confirm-level. This is equivalent to setting $OPAMNO to "true".
31
32       --package=PACKAGE
33           List all variables defined for the given package
34
35       -y, --yes
36           Answer yes to all opam yes/no questions without prompting. See also
37           --confirm-level. This is equivalent to setting $OPAMYES to "true".
38

COMMON OPTIONS

40       These options are common to all commands.
41
42       --best-effort
43           Don't fail if all requested packages can't be installed: try to
44           install as many as possible. Note that not all external solvers may
45           support this option (recent versions of aspcud or mccs should).
46           This is equivalent to setting $OPAMBESTEFFORT environment variable.
47
48       --cli=MAJOR.MINOR (absent=2.1)
49           Use the command-line interface syntax and semantics of MAJOR.MINOR.
50           Intended for any persistent use of opam (scripts, blog posts,
51           etc.), any version of opam in the same MAJOR series will behave as
52           for the specified MINOR release. The flag was not available in opam
53           2.0, so to select the 2.0 CLI, set the OPAMCLI environment variable
54           to 2.0 instead of using this parameter.
55
56       --color=WHEN
57           Colorize the output. WHEN must be one of always, never or auto.
58
59       --confirm-level=LEVEL
60           Confirmation level, LEVEL must be one of ask, no, yes or
61           unsafe-yes. Can be specified more than once. If --yes or --no are
62           also given, the value of the last --confirm-level is taken into
63           account. This is equivalent to setting  $OPAMCONFIRMLEVEL`.
64
65       --criteria=CRITERIA
66           Specify user preferences for dependency solving for this run.
67           Overrides both $OPAMCRITERIA and $OPAMUPGRADECRITERIA. For details
68           on the supported language, and the external solvers available, see
69           http://opam.ocaml.org/doc/External_solvers.html. A general guide to
70           using solver preferences can be found at
71           http://www.dicosmo.org/Articles/usercriteria.pdf.
72
73       --cudf=FILENAME
74           Debug option: Save the CUDF requests sent to the solver to
75           FILENAME-<n>.cudf.
76
77       --debug
78           Print debug message to stderr. This is equivalent to setting
79           $OPAMDEBUG to "true".
80
81       --debug-level=LEVEL
82           Like --debug, but allows specifying the debug level (--debug sets
83           it to 1). Equivalent to setting $OPAMDEBUG to a positive integer.
84
85       --git-version
86           Print the git version of opam, if set (i.e. you are using a
87           development version), and exit.
88
89       --help[=FMT] (default=auto)
90           Show this help in format FMT. The value FMT must be one of auto,
91           pager, groff or plain. With auto, the format is pager or plain
92           whenever the TERM env var is dumb or undefined.
93
94       --ignore-pin-depends
95           Ignore extra pins required by packages that get pinned, either
96           manually through opam pin or through opam install DIR. This is
97           equivalent to setting IGNOREPINDEPENDS=true.
98
99       --json=FILENAME
100           Save the results of the opam run in a computer-readable file. If
101           the filename contains the character `%', it will be replaced by an
102           index that doesn't overwrite an existing file. Similar to setting
103           the $OPAMJSON variable.
104
105       --no-aspcud
106           Removed in 2.1.
107
108       --no-auto-upgrade
109           When configuring or updating a repository that is written for an
110           earlier opam version (1.2), opam internally converts it to the
111           current format. This disables this behaviour. Note that
112           repositories should define their format version in a 'repo' file at
113           their root, or they will be assumed to be in the older format. It
114           is, in any case, preferable to upgrade the repositories manually
115           using opam admin upgrade [--mirror URL] when possible.
116
117       --no-self-upgrade
118           Opam will replace itself with a newer binary found at OPAMROOT/opam
119           if present. This disables this behaviour.
120
121       -q, --quiet
122           Disables --verbose.
123
124       --root=ROOT
125           Use ROOT as the current root path. This is equivalent to setting
126           $OPAMROOT to ROOT.
127
128       --safe, --readonly
129           Make sure nothing will be automatically updated or rewritten.
130           Useful for calling from completion scripts, for example. Will fail
131           whenever such an operation is needed ; also avoids waiting for
132           locks, skips interactive questions and overrides the $OPAMDEBUG
133           variable. This is equivalent to set environment variable $OPAMSAFE.
134
135       --solver=CMD
136           Specify the CUDF solver to use for resolving package installation
137           problems. This is either a predefined solver (this version of opam
138           supports builtin-mccs+lp(), builtin-mccs+glpk,
139           builtin-dummy-z3-solver, builtin-dummy-0install-solver, aspcud,
140           mccs, aspcud-old, packup), or a custom command that should contain
141           the variables %{input}%, %{output}%, %{criteria}%, and optionally
142           %{timeout}%. This is equivalent to setting $OPAMEXTERNALSOLVER.
143
144       --strict
145           Fail whenever an error is found in a package definition or a
146           configuration file. The default is to continue silently if
147           possible.
148
149       --switch=SWITCH
150           Use SWITCH as the current compiler switch. This is equivalent to
151           setting $OPAMSWITCH to SWITCH.
152
153       --use-internal-solver
154           Disable any external solver, and use the built-in one (this
155           requires that opam has been compiled with a built-in solver). This
156           is equivalent to setting $OPAMNOASPCUD or $OPAMUSEINTERNALSOLVER.
157
158       -v, --verbose
159           Be more verbose. One -v shows all package commands, repeat to also
160           display commands called internally (e.g. tar, curl, patch etc.)
161           Repeating n times is equivalent to setting $OPAMVERBOSE to "n".
162
163       --version
164           Show version information.
165
166       -w, --working-dir
167           Whenever updating packages that are bound to a local,
168           version-controlled directory, update to the current working state
169           of their source instead of the last committed state, or the ref
170           they are pointing to. As source directory is copied as it is, if it
171           isn't clean it may result on a opam build failure.This only affects
172           packages explicitly listed on the command-line.It can also be set
173           with $OPAMWORKINGDIR.
174

ENVIRONMENT

176       Opam makes use of the environment variables listed here. Boolean
177       variables should be set to "0", "no", "false" or the empty string to
178       disable, "1", "yes" or "true" to enable.
179
180       OPAMALLPARENS surround all filters with parenthesis.
181
182       OPAMASSUMEDEPEXTS see option `--assume-depexts'.
183
184       OPAMAUTOREMOVE see remove option `--auto-remove'.
185
186       OPAMBESTEFFORT see option `--best-effort'.
187
188       OPAMBESTEFFORTPREFIXCRITERIA sets the string that must be prepended to
189       the criteria when the `--best-effort' option is set, and is expected to
190       maximise the `opam-query' property in the solution.
191
192       OPAMBUILDDOC Removed in 2.1.
193
194       OPAMBUILDTEST Removed in 2.1.
195
196       OPAMCLI see option `--cli'.
197
198       OPAMCOLOR when set to always or never, sets a default value for the
199       `--color' option.
200
201       OPAMCONFIRMLEVEL see option `--confirm-level`. OPAMCONFIRMLEVEL has
202       priority over OPAMYES and OPAMNO.
203
204       OPAMCRITERIA specifies user preferences for dependency solving. The
205       default value depends on the solver version, use `config report' to
206       know the current setting. See also option --criteria.
207
208       OPAMCUDFFILE save the cudf graph to file-actions-explicit.dot.
209
210       OPAMCUDFTRIM controls the filtering of unrelated packages during CUDF
211       preprocessing.
212
213       OPAMCURL can be used to select a given 'curl' program. See OPAMFETCH
214       for more options.
215
216       OPAMDEBUG see options `--debug' and `--debug-level'.
217
218       OPAMDEBUGSECTIONS if set, limits debug messages to the space-separated
219       list of sections. Sections can optionally have a specific debug level
220       (for example, CLIENT:2 or CLIENT CUDF:2), but otherwise use
221       `--debug-level'.
222
223       OPAMDIGDEPTH defines how aggressive the lookup for conflicts during
224       CUDF preprocessing is.
225
226       OPAMDOWNLOADJOBS sets the maximum number of simultaneous downloads.
227
228       OPAMDROPWORKINGDIR overrides packages previously updated with
229       --working-dir on update. Without this variable set, opam would keep
230       them unchanged unless explicitly named on the command-line.
231
232       OPAMDRYRUN see option `--dry-run'.
233
234       OPAMEDITOR sets the editor to use for opam file editing, overrides
235       $EDITOR and $VISUAL.
236
237       OPAMERRLOGLEN sets the number of log lines printed when a sub-process
238       fails. 0 to print all.
239
240       OPAMEXTERNALSOLVER see option `--solver'.
241
242       OPAMFAKE see option `--fake'.
243
244       OPAMFETCH specifies how to download files: either `wget', `curl' or a
245       custom command where variables %{url}%, %{out}%, %{retry}%,
246       %{compress}% and %{checksum}% will be replaced. Overrides the
247       'download-command' value from the main config file.
248
249       OPAMFIXUPCRITERIA same as OPAMUPGRADECRITERIA, but specific to fixup.
250
251       OPAMIGNORECONSTRAINTS see install option `--ignore-constraints-on'.
252
253       OPAMIGNOREPINDEPENDS see option `--ignore-pin-depends'.
254
255       OPAMINPLACEBUILD see option `--inplace-build'.
256
257       OPAMJOBS sets the maximum number of parallel workers to run.
258
259       OPAMJSON log json output to the given file (use character `%' to index
260       the files).
261
262       OPAMKEEPBUILDDIR see install option `--keep-build-dir'.
263
264       OPAMKEEPLOGS tells opam to not remove some temporary command logs and
265       some backups. This skips some finalisers and may also help to get more
266       reliable backtraces.
267
268       OPAMLOCKED combination of `--locked' and `--lock-suffix' options.
269
270       OPAMLOGS logdir sets log directory, default is a temporary directory in
271       /tmp
272
273       OPAMMAKECMD set the system make command to use.
274
275       OPAMMERGEOUT merge process outputs, stderr on stdout.
276
277       OPAMNO answer no to any question asked, see options `--no` and
278       `--confirm-level`. OPAMNO is ignored if either OPAMCONFIRMLEVEL or
279       OPAMYES is set.
280
281       OPAMNOAGGREGATE with `opam admin check', don't aggregate packages.
282
283       OPAMNOASPCUD Deprecated.
284
285       OPAMNOAUTOUPGRADE disables automatic internal upgrade of repositories
286       in an earlier format to the current one, on 'update' or 'init'.
287
288       OPAMNOCHECKSUMS enables option --no-checksums when available.
289
290       OPAMNODEPEXTS disables system dependencies handling, see option
291       `--no-depexts'.
292
293       OPAMNOENVNOTICE Internal.
294
295       OPAMNOSELFUPGRADE see option `--no-self-upgrade'
296
297       OPAMPINKINDAUTO sets whether version control systems should be detected
298       when pinning to a local path. Enabled by default since 1.3.0.
299
300       OPAMPRECISETRACKING fine grain tracking of directories.
301
302       OPAMPREPRO set this to false to disable CUDF preprocessing. Less
303       efficient, but might help debugging solver issue.
304
305       OPAMREQUIRECHECKSUMS Enables option `--require-checksums' when
306       available (e.g. for `opam install').
307
308       OPAMRETRIES sets the number of tries before failing downloads.
309
310       OPAMREUSEBUILDDIR see option `--reuse-build-dir'.
311
312       OPAMROOT see option `--root'. This is automatically set by `opam env
313       --root=DIR --set-root'.
314
315       OPAMROOTISOK don't complain when running as root.
316
317       OPAMSAFE see option `--safe'.
318
319       OPAMSHOW see option `--show'.
320
321       OPAMSKIPUPDATE see option `--skip-updates'.
322
323       OPAMSKIPVERSIONCHECKS bypasses some version checks. Unsafe, for
324       compatibility testing only.
325
326       OPAMSOLVERALLOWSUBOPTIMAL (default `true') allows some solvers to still
327       return a solution when they reach timeout; while the solution remains
328       assured to be consistent, there is no guarantee in this case that it
329       fits the expected optimisation criteria. If `true', opam willcontinue
330       with a warning, if `false' a timeout is an error. Currently only the
331       builtin-z3 backend handles this degraded case.
332
333       OPAMSOLVERTIMEOUT change the time allowance of the solver. Default is
334       60.0, set to 0 for unlimited. Note that all solvers may not support
335       this option.
336
337       OPAMSTATS display stats at the end of command.
338
339       OPAMSTATUSLINE display a dynamic status line showing what's currently
340       going on on the terminal. (one of one of always, never or auto)
341
342       OPAMSTRICT fail on inconsistencies (file reading, switch import, etc.).
343
344       OPAMSWITCH see option `--switch'. Automatically set by `opam env
345       --switch=SWITCH --set-switch'.
346
347       OPAMUNLOCKBASE see install option `--unlock-base'.
348
349       OPAMUPGRADECRITERIA specifies user preferences for dependency solving
350       when performing an upgrade. Overrides OPAMCRITERIA in upgrades if both
351       are set. See also option --criteria.
352
353       OPAMUSEINTERNALSOLVER see option `--use-internal-solver'.
354
355       OPAMUSEOPENSSL force openssl use for hash computing.
356
357       OPAMUTF8 use UTF8 characters in output (one of one of always, never or
358       auto). By default `auto', which is determined from the locale).
359
360       OPAMUTF8MSGS use extended UTF8 characters (camels) in opam messages.
361       Implies OPAMUTF8. This is set by default on OSX only.
362
363       OPAMVALIDATIONHOOK if set, uses the `%{hook%}' command to validate an
364       opam repository update.
365
366       OPAMVERBOSE see option `--verbose'.
367
368       OPAMVERSIONLAGPOWER do not use.
369
370       OPAMWITHDOC see install option `--with-doc'.
371
372       OPAMWITHTEST see install option `--with-test.
373
374       OPAMWORKINGDIR see option `--working-dir'.
375
376       OPAMYES see options `--yes' and `--confirm-level`. OPAMYES has has
377       priority over OPAMNO and is ignored if OPAMCONFIRMLEVEL is set.
378
379       OPAMVAR_var overrides the contents of the variable var when
380       substituting `%{var}%` strings in `opam` files.
381
382       OPAMVAR_package_var overrides the contents of the variable package:var
383       when substituting `%{package:var}%` strings in `opam` files.
384

CLI VERSION

386       All scripts and programmatic invocations of opam should use `--cli' in
387       order to ensure that they work seamlessly with future versions of the
388       opam client. Additionally, blog posts or other documentation can
389       benefit, as it prevents information from becoming stale.
390
391       Although opam only supports roots (~/.opam/) for the current version,
392       it does provide backwards compatibility for its command-line interface.
393
394       Since CLI version support was only added in opam 2.1, use OPAMCLI to
395       select 2.0 support (as opam 2.0 will just ignore it), and `--cli=2.1'
396       for 2.1 (or later) versions, since an environment variable controlling
397       the parsing of syntax is brittle. To this end, opam displays a warning
398       if OPAMCLI specifies a valid version other than 2.0, and also if
399       `--cli=2.0' is specified.
400
401       The command-line version is selected by using the `--cli' option or the
402       OPAMCLI environment variable. `--cli' may be specified morethan once,
403       where the last instance takes precedence. OPAMCLI is only inspected if
404       `--cli' is not given.
405

EXIT STATUS

407       As an exception to the following, the `exec' command returns 127 if the
408       command was not found or couldn't be executed, and the command's exit
409       value otherwise.
410
411       0   Success, or true for boolean queries.
412
413       1   False. Returned when a boolean return value is expected, e.g. when
414           running with --check, or for queries like opam lint.
415
416       2   Bad command-line arguments, or command-line arguments pointing to
417           an invalid context (e.g. file not following the expected format).
418
419       5   Not found. You requested something (package, version, repository,
420           etc.) that couldn't be found.
421
422       10  Aborted. The operation required confirmation, which wasn't given.
423
424       15  Could not acquire the locks required for the operation.
425
426       20  There is no solution to the user request. This can be caused by
427           asking to install two incompatible packages, for example.
428
429       30  Error in package definition, or other metadata files. Using
430           --strict raises this error more often.
431
432       31  Package script error. Some package operations were unsuccessful.
433           This may be an error in the packages or an incompatibility with
434           your system. This can be a partial error.
435
436       40  Sync error. Could not fetch some remotes from the network. This can
437           be a partial error.
438
439       50  Configuration error. Opam or system configuration doesn't allow
440           operation, and needs fixing.
441
442       60  Solver failure. The solver failed to return a sound answer. It can
443           be due to a broken external solver, or an error in solver
444           configuration.
445
446       99  Internal error. Something went wrong, likely due to a bug in opam
447           itself.
448
449       130 User interrupt. SIGINT was received, generally due to the user
450           pressing Ctrl-C.
451

FURTHER DOCUMENTATION

453       See https://opam.ocaml.org/doc.
454

AUTHORS

456       Vincent Bernardoff <vb@luminar.eu.org>
457       Raja Boujbel <raja.boujbel@ocamlpro.com>
458       Roberto Di Cosmo <roberto@dicosmo.org>
459       Thomas Gazagnaire <thomas@gazagnaire.org>
460       Louis Gesbert <louis.gesbert@ocamlpro.com>
461       Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>
462       Anil Madhavapeddy <anil@recoil.org>
463       Guillem Rieu <guillem.rieu@ocamlpro.com>
464       Ralf Treinen <ralf.treinen@pps.jussieu.fr>
465       Frederic Tuong <tuong@users.gforge.inria.fr>
466

BUGS

468       Check bug reports at https://github.com/ocaml/opam/issues.
469
470
471
472Opam 2.1.5                                                         OPAM-VAR(1)
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