1opam-var(1) Opam Manual opam-var(1)
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6 opam-var - Prints the value associated with a given variable
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9 opam var [OPTION]... [VAR]
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12 With a VAR argument, prints the value associated with VAR. Without
13 argument, lists the opam variables currently defined. This command is a
14 shortcut to `opam config var` and `opam config list`.
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17 --package=PACKAGE
18 List all variables defined for the given package
19
21 These options are common to all commands.
22 --best-effort
24 Don't fail if all requested packages can't be installed: try to
25 install as many as possible. Note that not all external solvers may
26 support this option (recent versions of aspcud or mccs should).
27 --color=WHEN
29 Colorize the output. WHEN must be one of `always', `never' or
30 `auto'.
31 --criteria=CRITERIA
33 Specify user preferences for dependency solving for this run.
34 Overrides both $OPAMCRITERIA and $OPAMUPGRADECRITERIA. For details
35 on the supported language, and the external solvers available, see
36 http://opam.ocaml.org/doc/Specifying_Solver_Preferences.html. A
37 general guide to using solver preferences can be found at
38 http://www.dicosmo.org/Articles/usercriteria.pdf.
39 --cudf=FILENAME
41 Debug option: Save the CUDF requests sent to the solver to
42 FILENAME-<n>.cudf.
43 --debug
45 Print debug message to stderr. This is equivalent to setting
46 $OPAMDEBUG to "true".
47 --debug-level=LEVEL
49 Like --debug, but allows specifying the debug level (--debug sets
50 it to 1). Equivalent to setting $OPAMDEBUG to a positive integer.
51 --git-version
53 Print the git version of opam, if set (i.e. you are using a
54 development version), and exit.
55 --help[=FMT] (default=auto)
57 Show this help in format FMT. The value FMT must be one of `auto',
58 `pager', `groff' or `plain'. With `auto', the format is `pager` or
59 `plain' whenever the TERM env var is `dumb' or undefined.
60 --ignore-pin-depends
62 Ignore extra pins required by packages that get pinned, either
63 manually through opam pin or through opam install DIR. This is
64 equivalent to setting IGNOREPINDEPENDS=true.
65 --json=FILENAME
67 Save the results of the opam run in a computer-readable file. If
68 the filename contains the character `%', it will be replaced by an
69 index that doesn't overwrite an existing file. Similar to setting
70 the $OPAMJSON variable.
71 --no-auto-upgrade
73 When configuring or updating a repository that is written for an
74 earlier opam version (1.2), opam internally converts it to the
75 current format. This disables this behaviour. Note that
76 repositories should define their format version in a 'repo' file at
77 their root, or they will be assumed to be in the older format. It
78 is, in any case, preferable to upgrade the repositories manually
79 using opam admin upgrade [--mirror URL] when possible.
80 --no-self-upgrade
82 Opam will replace itself with a newer binary found at OPAMROOT/opam
83 if present. This disables this behaviour.
84 -q, --quiet
86 Disables --verbose.
87 --root=ROOT
89 Use ROOT as the current root path. This is equivalent to setting
90 $OPAMROOT to ROOT.
91 --safe, --readonly
93 Make sure nothing will be automatically updated or rewritten.
94 Useful for calling from completion scripts, for example. Will fail
95 whenever such an operation is needed ; also avoids waiting for
96 locks, skips interactive questions and overrides the $OPAMDEBUG
97 variable.
98 --solver=CMD
100 Specify the CUDF solver to use for resolving package installation
101 problems. This is either a predefined solver (this version of opam
102 supports builtin-mccs+lp(), builtin-mccs+glpk, aspcud, mccs,
103 aspcud-old, packup), or a custom command that should contain the
104 variables %{input}%, %{output}%, %{criteria}%, and optionally
105 %{timeout}%.
106 --strict
108 Fail whenever an error is found in a package definition or a
109 configuration file. The default is to continue silently if
110 possible.
111 --switch=SWITCH
113 Use SWITCH as the current compiler switch. This is equivalent to
114 setting $OPAMSWITCH to SWITCH.
115 --use-internal-solver, --no-aspcud
117 Disable any external solver, and use the built-in one (this
118 requires that opam has been compiled with a built-in solver).
119 -v, --verbose
121 Be more verbose. One -v shows all package commands, repeat to also
122 display commands called internally (e.g. tar, curl, patch etc.)
123 Repeating n times is equivalent to setting $OPAMVERBOSE to "n".
124 --version
126 Show version information.
127 -w, --working-dir
129 Whenever updating packages that are bound to a local,
130 version-controlled directory, update to the current working state
131 of their source instead of the last committed state, or the ref
132 they are pointing to. This only affects packages explicitly listed
133 on the command-line.
134 -y, --yes
136 Answer yes to all yes/no questions without prompting. This is
137 equivalent to setting $OPAMYES to "true".
138
140 Opam makes use of the environment variables listed here. Boolean
141 variables should be set to "0", "no", "false" or the empty string to
142 disable, "1", "yes" or "true" to enable.
143 OPAMCOLOR, when set to always or never, sets a default value for the
145 --color option.
146 OPAMCRITERIA specifies user preferences for dependency solving. The
148 default value depends on the solver version, use `config report` to
149 know the current setting. See also option --criteria
150 OPAMCURL can be used to select a given 'curl' program. See OPAMFETCH
152 for more options.
153 OPAMDEBUG see options `--debug' and `--debug-level'.
155 OPAMDOWNLOADJOBS sets the maximum number of simultaneous downloads.
157 OPAMERRLOGLEN sets the number of log lines printed when a sub-process
159 fails. 0 to print all.
160 OPAMEXTERNALSOLVER see option `--solver'.
162 OPAMFETCH specifies how to download files: either `wget', `curl' or a
164 custom command where variables %{url}%, %{out}%, %{retry}%,
165 %{compress}% and %{checksum}% will be replaced. Overrides the
166 'download-command' value from the main config file.
167 OPAMJOBS sets the maximum number of parallel workers to run.
169 OPAMJSON log json output to the given file (use character `%' to index
171 the files)
172 OPAMLOCK see option `--lock'.
174 OPAMNOAUTOUPGRADE disables automatic internal upgrade of repositories
176 in an earlier format to the current one, on 'update' or 'init'.
177 OPAMKEEPLOGS tells opam to not remove some temporary command logs and
179 some backups. This skips some finalisers and may also help to get more
180 reliable backtraces
181 OPAMLOCKRETRIES sets the number of tries after which OPAM gives up
183 acquiring its lock and fails. <= 0 means infinite wait.
184 OPAMNO answer no to any question asked.
186 OPAMNOASPCUD see option `--no-aspcud'.
188 OPAMNOSELFUPGRADE see option `--no-self-upgrade'.
190 OPAMPINKINDAUTO sets whether version control systems should be detected
192 when pinning to a local path. Enabled by default since 1.3.0.
193 OPAMREQUIRECHECKSUMS Enables option `--require-checksums' when
195 available (e.g. for `opam install`).
196 OPAMRETRY sets the number of tries before failing downloads.
198 OPAMROOT see option `--root'. This is automatically set by `opam env
200 --root=DIR --set-root'.
201 OPAMROOTISOK don't complain when running as root.
203 OPAMSAFE see option `--safe'
205 OPAMSKIPVERSIONCHECKS bypasses some version checks. Unsafe, for
207 compatibility testing only.
208 OPAMSOLVERTIMEOUT change the time allowance of the solver. Default is
210 60.0, set to 0 for unlimited. Note that all solvers may not support
211 this option.
212 OPAMSTATUSLINE display a dynamic status line showing what's currently
214 going on on the terminal. (one of one of `always', `never' or `auto')
215 OPAMSWITCH see option `--switch'. Automatically set by `opam env
217 --switch=SWITCH --set-switch'.
218 OPAMUPGRADECRITERIA specifies user preferences for dependency solving
220 when performing an upgrade. Overrides OPAMCRITERIA in upgrades if both
221 are set. See also option --criteria
222 OPAMUSEINTERNALSOLVER see option `--use-internal-solver'.
224 OPAMUTF8 use UTF8 characters in output (one of one of `always', `never'
226 or `auto'). By default `auto', which is determined from the locale).
227 OPAMUTF8MSGS use extended UTF8 characters (camels) in opam messages.
229 Implies OPAMUTF8. This is set by default on OSX only.
230 OPAMVAR_var overrides the contents of the variable var when
232 substituting `%{var}%` strings in `opam` files.
233 OPAMVAR_package_var overrides the contents of the variable package:var
235 when substituting `%{package:var}%` strings in `opam` files.
236 OPAMVERBOSE see option `--verbose'.
238 OPAMYES see option `--yes'.
240
242 As an exception to the following, the `exec' command returns 127 if the
243 command was not found or couldn't be executed, and the command's exit
244 value otherwise.
245 0 Success, or true for boolean queries.
247 1 False. Returned when a boolean return value is expected, e.g. when
249 running with --check, or for queries like opam lint.
250 2 Bad command-line arguments, or command-line arguments pointing to
252 an invalid context (e.g. file not following the expected format).
253 5 Not found. You requested something (package, version, repository,
255 etc.) that couldn't be found.
256 10 Aborted. The operation required confirmation, which wasn't given.
258 15 Could not acquire the locks required for the operation.
260 20 There is no solution to the user request. This can be caused by
262 asking to install two incompatible packages, for example.
263 30 Error in package definition, or other metadata files. Using
265 --strict raises this error more often.
266 31 Package script error. Some package operations were unsuccessful.
268 This may be an error in the packages or an incompatibility with
269 your system. This can be a partial error.
270 40 Sync error. Could not fetch some remotes from the network. This can
272 be a partial error.
273 50 Configuration error. Opam or system configuration doesn't allow
275 operation, and needs fixing.
276 60 Solver failure. The solver failed to return a sound answer. It can
278 be due to a broken external solver, or an error in solver
279 configuration.
280 99 Internal error. Something went wrong, likely due to a bug in opam
282 itself.
283 130 User interrupt. SIGINT was received, generally due to the user
285 pressing Ctrl-C.
286
288 See https://opam.ocaml.org/doc.
289
291 Vincent Bernardoff <vb@luminar.eu.org>
292 Raja Boujbel <raja.boujbel@ocamlpro.com>
293 Roberto Di Cosmo <roberto@dicosmo.org>
294 Thomas Gazagnaire <thomas@gazagnaire.org>
295 Louis Gesbert <louis.gesbert@ocamlpro.com>
296 Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>
297 Anil Madhavapeddy <anil@recoil.org>
298 Guillem Rieu <guillem.rieu@ocamlpro.com>
299 Ralf Treinen <ralf.treinen@pps.jussieu.fr>
300 Frederic Tuong <tuong@users.gforge.inria.fr>
301
303 Check bug reports at https://github.com/ocaml/opam/issues.
304Opam 2.0.1 opam-var(1)