4 This is a wrapper tool for cargo, the Rust build tool and package
7 * Conveniently use local crates, including completely
10 * Perform out-of-tree builds, including in an account with
11 no write access to the source tree.
13 * Provide convenience aliases for target architecture names.
15 * Make the default be offline (ie, not to access the internet)
17 These functions are of course configurable.
19 The primary source of information for nailing-cargo is the file
20 `../Cargo.nail` (which is in TOML syntax). You put `Cargo.nail`
21 alongside the top-level git repositories you are working with, and
22 invoke nailing-cargo from the git directory containing the Rust
23 package you want to build.
28 nailing-cargo is designed to be run out of a git clone:
31 $ git clone https://salsa.debian.org/iwj/nailing-cargo.git
32 $ ln -s `pwd`/nailing-cargo/nailing-cargo ~/bin
35 It is self-contained, depending only on a reasonably functional Perl
38 Most basic example usage
39 ------------------------
48 $ nailing-cargo generate-lockfile
52 Documentation table of contents
53 -------------------------------
55 <!-- TOC autogenerated by ./markdown-toc-filter, do not edit -->
57 * [Introduction](#nailing-cargo)
58 * [Installing](#installing)
59 * [Most basic example usage](#most-basic-example-usage)
60 * [Documentation table of contents](#documentation-table-of-contents)
61 * [Using local crates, or locally modified crates](#using-local-crates-or-locally-modified-crates)
62 * [How nailing-cargo helps with using local crates](#how-nailing-cargo-helps-with-using-local-crates)
63 * [Telling nailing-cargo how to massage `Cargo.toml`](#telling-nailing-cargo-how-to-massage-cargo.toml)
64 * [Out-of-tree builds](#out-of-tree-builds)
65 * [How nailing-cargo helps with out-of-tree builds](#how-nailing-cargo-helps-with-out-of-tree-builds)
66 * [Configuring out-of-tree builds](#configuring-out-of-tree-builds)
67 * [Target architecture convenience aliases](#target-architecture-convenience-aliases)
68 * [Default change to offline mode](#default-change-to-offline-mode)
69 * [Invocation and command-line option reference](#invocation-and-command-line-option-reference)
72 * [Environment of the build command](#environment-of-the-build-command)
73 * [Configuration reference](#configuration-reference)
74 * [Source directories and packages (toplevel)](#source-directories-and-packages-toplevel)
75 * [`[alt_cargolock]`: Alternative `Cargo.lock` filename](#alt_cargolock-alternative-cargo.lock-filename)
76 * [`[oot]`: Out-of-tree build support](#oot-out-of-tree-build-support)
77 * [`[arch]`: Architecture convenience aliases](#arch-architecture-convenience-aliases)
78 * [`[misc]`: Miscellaneous individual nailing-cargo config](#misc-miscellaneous-individual-nailing-cargo-config)
79 * [Limitations and bugs](#limitations-and-bugs)
80 * [Contributing and legal](#contributing-and-legal)
83 Using local crates, or locally modified crates
84 ==============================================
86 cargo does not work well with local crates,
87 especially completely unpublished ones.
88 (See [issue#6713](https://github.com/rust-lang/cargo/issues/6713),
89 [stackoverflow](https://stackoverflow.com/questions/33025887/how-to-use-a-local-unpublished-crate),
90 [issue#1481](https://github.com/rust-lang/cargo/issues/1481),
91 [my blog](https://diziet.dreamwidth.org/1805.html).)
93 Using a local version of a crate should be possible without putting
94 paths into your `Cargo.toml` and without editing complex
97 How nailing-cargo helps with using local crates
98 -----------------------------------------------
100 nailing-cargo temporarily edits all the `Cargo.toml` files in all the
101 subdirectories you mention, to refer to each other; then it runs
102 cargo; and then it puts everything back.
104 Telling nailing-cargo how to massage `Cargo.toml`
105 -------------------------------------------------
107 To find the subdirectories, and the packages, it looks for `subdirs`
108 and `packages` in `Cargo.nail`.
110 For straightforward use, write `subdirs` as a multi-line string
111 containing a list of subdirectory names one per line. In each of
112 these directories `Cargo.toml` will be massaged, and the package there
113 will be used for other massaged `Cargo.toml`s.
115 See "Configuration reference", below, for full details.
120 It is often desirable to run builds in a way that does not write to
121 the source tree. cargo's enthusiastic approach to the dependency
122 management task means that it is a good idea to try to insulate your
123 main working environment from the many things cargo has decided to
124 download and execute.
126 However, when you tell cargo to do an out of tree build (using
127 `--manifest-path`) it will insist on `Cargo.lock` being in the source
128 directory, and often will insist on writing to it.
130 How nailing-cargo helps with out-of-tree builds
131 -----------------------------------------------
133 nailing-cargo (configured appropriately) copies files back and forth
134 to between the source and build directories, and runs cargo as your
137 The `Cargo.lock` must still be saved in your source tree somewhere.
138 nailing-cargo arranges this for you. You can either put this file in
139 `.gitignore`; or commit it to git; or you can tell nailing-cargo to
140 save it as something like `Cargo.lock.example`.
142 Configuring out-of-tree builds
143 ------------------------------
145 To enable out-of-tree-builds, put an `[oot]` section in your
146 `Cargo.nail` or one of nailing-cargo's other config files.
147 In that section, specify at least `use`.
149 Also, specify `dir`, or create a symlink `Build` next to `Cargo.nail`,
150 pointing to to your build area.
158 will have nailing-cargo run `ssh rustcargo@localhost` to
161 Target architecture convenience aliases
162 =======================================
164 If you are cross-building you may need to tell cargo `--target=`.
165 The architecture names are quite long and inconvenient.
167 A simple shell alias would help a lot, except that cargo rejects
168 `--target=` when it thinks it's not needed.
170 In your nailing-cargo config, you can write something like
171 `arch.RPI='arm-unknown-linux-gnueabihf'`. Then `nailing-cargo -ARPI`
172 will DTRT. In fact, you do not even need to specify that particular
173 arch alias, since it is built-in to nailing-cargo.
175 Default change to offline mode
176 ==============================
178 It seems to me that build tools should be explicit about their use of
179 the network. So by default, nailing-cargo passes `--offline` to
182 If you disagree with my opinion, write `misc.online=true` in your
183 nailing-cargo configuration. `misc.online=false`, and command line
184 options, are also available, for overriding.
186 Invocation and command-line option reference
187 ============================================
193 1$ nailing-cargo <nailing-opts> <cargo-opts> [--] <subcmd>...
194 2$ nailing-cargo <nailing-opts> --- <cargo> <cargo-opts> [--] <subcmd>...
195 3$ nailing-cargo <nailing-opts> --- [--] <build-command>...
197 Ususally the `--` is not needed. (It should generally be passed by
198 programs which wrap nailing-cargo. See below.)
200 In usage 1, nailing-cargo runs `cargo` (from `PATH`). In the usage 2
201 nailing-cargo runs `<cargo>`. In both these cases it adds its own
202 options to control cargo's behaviour. In both of these cases
203 nailing-cargo looks at `<subcmd>` to determine the cargo subcommand
204 being run: this controls various defaults, to try to do the right
207 In the third syntax, nailing-cargo runs `<build-command>...` without
208 additional arguments and does not attempt to identify the cargo
209 subcommand(s) that it will run. Possibly it will be necessary to pass
210 `--online` or `--cargo-lock-update`, or even `--cargo-*arg*`
212 ### Invocation argument disambiguation rules ###
214 For authors of tools which call nailing-cargo (and pedants):
216 The usages overlap in syntax! nailing-cargo follows the following
217 rules when interpreting its command line:
219 * The first option not recognised as a nailing-cargo option is
220 treated as the start of the `<cargo-opts>`.
222 * `<cargo-opts>` are terminated by `--` (which is removed) or the
223 first argument which does not start with a `-`.
225 (It is not possible to get nailing-cargo to pass the value `--`
226 as a separate argument to a cargo global option, but cargo global
227 options can typically take the values cuddled with `=`, so doing
228 that is not necessary.)
230 * After `---`, nailing-cargo will search for a `--`, to the end of
231 the arguments if necessary. The position of the `--` determines
232 whether this is usage 2 or usage 3, and what `<subcmd>` is.
234 If the arguments after `nailing-cargo ... ---` might contain `--`
235 anywhere, an explicit `--` should be passed.
237 * If no `--` appears after `---`, the word after `---` is the
238 command to run; if its final pathname component contains the
239 string `cargo`, it is treated as `<cargo>` (implying usage 2 and
240 the search for `<subcmd>`). Otherwise it is treated as
241 `<build-command>` (usage 3).
246 * `-v`: Increase verbosity. Default is 1.
248 * `-q`: Set verbosity to 0.
250 * `-D`: Increase amount of debugging dump.
252 * `-n`: "No action": stop after writing `Cargo.toml.nailing~`
253 everywhere, and do not run any build command.
255 * `-T<arch>` | `--target=<arch>`
257 Specify target architecture.
259 This option translates to a `--target=<arch>` option to cargo
260 (when the subcommand accepts it).
262 If `<arch>` starts with a capital ascii letter, it is an alias
263 for some other arch: it is looked up in the configuration, and
264 then in the builtin arch alias list. The builtin list is
265 equivalent to: `[arch]` `RPI='arm-unknown-linux-gnueabihf'`.
269 Behave as if the build command were `cargo <subcommand>`.
271 This influences the logic which tries to determine which
272 options to pass to cargo, whether cargo needs to be online, and
273 whether cargo might want to update `Cargo.lock`.
275 But this option does not affect which build command (and which
276 cargo subcommand) is actually run.
280 Behave as if the build command will not run cargo.
282 This suppresses the addition of cargo command line options and
283 makes nailing-cargo assumes that the build command will not
284 need to update `Cargo.lock`.
285 But this option does not affect which build command is actually
288 * `-u` | `--cargo-lock-update` | `-U` | `--no-cargo-lock-update`
290 Enables, or disables, the dance to allow `Cargo.lock` (or
291 alternative) to be updated in the source directory.
293 With this dance enabled the `Cargo.lock` and `Cargo.toml` are
294 copied to the build directory along with a skeleton just big
295 enough to fool cargo. After cargo has run, the resulting
296 `Cargo.lock` is copied back to the source tree.
298 This makes no sense with in-tree builds.
300 Default is no update unless the cargo subcommand will want it.
302 * `--cargo-args=<ena><opt>[,<ena><opt>...]`
304 Overrides the logic for choosing which cargo options should be
305 passed to the build command.
306 The value is a comma-separated list of `<ena><opt>`.
308 `<opt>` is one of the arguments that nailing-cargo might pass
309 to cargo: `manifest-path`, `locked`, `target-dir`, `offline`,
311 (Note these must be specified
312 without the leading `--` and without any value.) `<opt>` may
313 also be `all` in which case the setting for all options is
316 The specs (maybe multiple `--cargo-args` options) are
317 cumulative and are processed in order. These options override
318 `-c`, `-C`. They can also effectively override other options
319 to nailing-cargo, such as `--offline` or `--target`.
323 * `@`: Decide automatically for this option (default).
324 * `+`: Definitely pass this option
325 * `-`: Definitely do not pass this option
326 * `_`: Definitely do not pass this option - and do not mind if `<opt>` is not known to nailing-cargo.
328 * `-T` | `--no-cargo-target-dir-arg` | `-t` | `--cargo-target-dir-arg`
330 `-T` suppresses `--target-dir`; `-t` un-suppresses it. Only
331 makes any difference with `-m`, since otherwise no
332 `--target-dir` would be passed anyway. Additionally this is
333 done automatically when nailing-cargo sees that the cargo
334 subcommand is one which needs it, eg `fetch`.
336 * `-o` | `--online` | `-O` | `--offline`
338 Whether to allow cargo to make network access. nailing-cargo
339 always passes `--offline` to cargo, unless `--online` is in
340 force. The default value depends on the configuration and the
341 cargo subcommand - see `[misc]` `online` in "Configuration".
343 Arguments to the build command
344 ------------------------------
347 * `-m` | `--cargo-manifest-args` | `-M` | `--no-cargo-manifest-args`
349 Controls whether we add cargo command line options, relating to
350 finding `Cargo.toml`, to the command to run.
352 Default is to add them if we are doing an out-of-tree build,
353 unless we are doing the dance to update the `Cargo.lock` (see
354 above) since in that case all the relevant files can be found
355 by cargo in the build directory.
357 The arguments added are
359 --manifest-path=<path/to/Cargo.toml>
363 Environment of the build command
364 --------------------------------
366 nailing-cargo passes these environment variables to the build command:
368 * `NAILINGCARGO_WORKSPHERE`: invocation `..` (parent)
369 * `NAILINGCARGO_MANIFEST_DIR`: invocation `.` (invocation directory)
370 * `NAILINGCARGO_BUILD_DIR`: build directory (even if same as source)
371 * `NAILINGCARGO_BUILDSPHERE`: only set if out of tree: parent of build dir.
373 All of these are absolute paths.
375 Configuration reference
376 =======================
378 nailing-cargo reads these configuration files:
380 /etc/nailing-cargo/cfg.toml
381 ~/.nailing-cargo.toml
382 ./.nailing-cargo.toml
383 ../Nailing-Cargo.toml
386 Settings in later-mentioned files override ones in earlier-mentioned
389 Source directories and packages (toplevel)
390 ------------------------------------------
392 Note that unlike everything else, these keys (`packages` and
393 `subdirs`) are read only from `Cargo.nail` (see "Limitations and
396 These keys specify a combination of (i) a mapping from package name to
397 source subdirectory (ii) a set of subdirectories whose `Cargo.toml`
400 * `packages`: a map keyed by package name, giving the subdirectory
403 This causes each mentioned subdirectory's `Cargo.toml` to be
404 massaged, and records that subdirectory as the source for that
405 package. (nailing-cargo will check that subdirectory actually
406 contains the indicated package.)
408 Each value can be just the subdirectory name (eg `[packages]`
409 `mylibrary='mylibrary-test'`) or itself a map with the key `subdir`
410 (eg `[packages.mylibrary]` `subdir='mylibrary-test'`).
412 * `subdirs`: a list of subdirectory names to process.
414 Each subdirectory's `Cargo.toml` will be massaged. Also, the
415 subdirectory will be examined to see what package it contains; it
416 will then be used as the source for that package, unless that
417 package appears in an entry in `packages`, or an earlier entry in
420 This can be a list of strings (eg `subdirs =
421 ['myproject','mylibrary']`). Or it can be single multi-line
422 string containing one subdirectory name per line; in that
423 case, `#`-comments are supported and tabs and spaces are ignored
424 (see "Most basic example usage" above.)
426 In each case the subdirectory should usually be a relative pathname;
427 it is relative to the directory containing `Cargo.nail`.
429 `[alt_cargolock]`: Alternative `Cargo.lock` filename
430 ----------------------------------------------------
432 To control use of alternative `Cargo.lock` filename, use the section
433 `[alt_cargolock]`. Settings here:
435 * `file = <some leafname>`.
437 * `file = true`: Equivalent to `file = "Cargo.lock.example"`.
438 (This is the default.)
440 * `file = false`: Disables this feature.
442 * `force = false`: Uses the alternative filename only if it
443 already exists. (This is the default.)
445 * `force = true`: Always uses the alternative filename.
447 `[oot]`: Out-of-tree build support
448 ----------------------------------
450 * `dir`: The build directory. If relative, it is relative to the
451 parent of the invocation directory (and could be a symlink then).
452 Default is `Build` (assuming `use` is specified).
454 The build directory will contain one subdir for each package: each
455 subdir in the build dir corresponds to one source dir where
456 nailing-cargo was invoked. nailing-cargo will arrange to create
457 these subdirectories, so the build directory can start out empty.
459 * `use`: How to become the build user. Needs to be combined
460 with other setting(s):
462 * `ssh`: Use ssh. `user` must be given as well and can be
463 a username on localhost, or the `<user>@<host>`
466 * `command_args`: `command` must be specified as a list,
467 specifying a command and arguments which work like `nice`.
469 * `command_sh`: `command` must be specified as a list,
470 specifying a command and arguments which work like `sh -c`.
472 * `null`: Run builds as the same user.
474 * `really`: Use `really` from `chiark-really.deb`.
475 `user` must be given as well.
477 * `disable': Disable this feature, even if `dir` is set.
479 * `command`: The command to run for `command_sh` or `command_args`.
481 * `user`: The local username for `really` and `ssh`, or
482 `<user>@<host>` for `ssh`.
484 `[arch]`: Architecture convenience aliases
485 ------------------------------------------
487 This is a map from archictecture aliases to full cargo architecture
488 names. The keys are the aliases; each entry should be a string, the
489 cargo architecture name.
491 Only keys starting with an ascii uppercase letter are relevant, since
492 other names are not looked up in this alias map.
494 `[misc]`: Miscellaneous individual nailing-cargo config
495 -------------------------------------------------------
497 * `online`: boolean, specifying whether to pass `--offline` to cargo
498 (cargo's default is online mode). The default is offline, unless
499 nailing-cargo can see that the cargo subcommand being invoked is
500 one which requires online access (currently, `fetch`), in which
501 case the default is online.
506 * nailing-cargo temporarily dirties your source trees, including
507 particularly `Cargo.toml` and `Cargo.lock`; and if nailing-cargo
508 crashes or is interrupted these changes may be left behind.
509 Unfortunately it is not possible to avoid this temporary dirtying
510 because the cargo team have deliberately made cargo inflexible -
511 [issue#6715](https://github.com/rust-lang/cargo/issues/6715).
512 At least, running nailing-cargo again will clean up any mess
513 left by an interrupted run.
515 * Out of tree builds require a unified filesystem view: eg, different
516 users on the same host, NFS, or something.
518 Specifically, the invocation and build execution environments must
519 both have visibility of the source and build directories, at the
520 same absolute pathnames. The invocation environment must be able
521 to write to the build environment (but vice versa is not
524 This could be improved.
526 * The alternative `Cargo.lock` filename must currently be a leafname. I
527 think fixing this just involves review to check other values work
530 * The alternative `Cargo.lock` file must be on the same filesystem
531 as the source tree. This is not so easy to fix; we would want the
532 existing algorithm but a fallback for the different-filsystem case.
534 * `Cargo.nail` is unconditionally looked for in the parent directory.
535 Ideally this should be configurable, and also perhaps be able to
536 combine multiple `Cargo.nail` files? Relatedly, although
537 nailing-cargo can read multiple config files, it can only handle
538 one file specifying directories and packages.
540 * nailing-cargo uses a single lockfile alongside your `Cargo.nail`,
541 rather than a more sophisticated scheme involving locking
542 particular directories. This means that if you run multiple
543 copies of nailing-cargo at once, in different directories, but
544 with `Cargo.nail` files which imply overlapping sets of package
545 directories, things will go Badly Wrong.
547 Contributing and legal
548 ======================
550 nailing-cargo is Free Software.
552 Please help improve it. Contributions (to address the limitations, or
553 to add new facilities to help work with cargo) are welcome by email to
554 `ijackson@chiark.greenend.org.uk` or via the [Salsa
555 project](https://salsa.debian.org/iwj/nailing-cargo).
557 If you plan to do substantial work, please do get in touch with a
558 sketch of your proposed changes.
563 This project accepts contributions based on the git commit
564 Signed-off-by convention, by which the contributors certify their
565 contributions according to the Developer Certificate of Origin version
566 1.1 - see the file DEVELOPER-CERTIFICATE.
568 Copyright (C) 2019-2020 Ian Jackson and others
570 This program is free software: you can redistribute it and/or modify
571 it under the terms of the GNU Affero General Public License as
572 published by the Free Software Foundation, either version 3 of the
573 License, or (at your option) any later version.
575 This program is distributed in the hope that it will be useful,
576 but WITHOUT ANY WARRANTY; without even the implied warranty of
577 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
578 GNU Affero General Public License for more details.
580 You should have received a copy of the GNU Affero General Public License
581 along with this program. If not, see <http://www.gnu.org/licenses/>.
583 Individual files generally contain the following tag in the copyright
584 notice, instead of the full licence grant text:
586 SPDX-License-Identifier: AGPL-3.0-or-later
588 As is conventional, this should be read as a licence grant.